Aerosol provision system

ABSTRACT

An aerosol provision system comprising a reservoir for aerosolisable material; a wick configured to receive the aerosolizable material from the reservoir, a vaporizer configured to vaporize the aerosolizable material received in the wick, wherein the aerosol provision system is configured to measure at least one parameter of the wick to determine a status of the wick The parameter may be the moisture content of the wick, at least one physical dimension of the wick, and/or an optical parameter, such as the color of an external surface of the wick, or the reflectivity of an external surface of the wick.

PRIORITY CLAIM

The present application is a National Phase entry of PCT Application No.PCT/GB2021/052354, filed Sep. 10, 2021, which claims priority from GBApplication No. 2014905.0, filed Sep. 22, 2020, GB Application No.2014916.7, filed Sep. 22, 2020 and GB Application No. 2014924.1, filedSep. 22, 2020, each of which hereby fully incorporated herein byreference.

FIELD

The present disclosure relates to aerosol provision systems such asnicotine delivery systems (e.g. electronic cigarettes and the like).

BACKGROUND

Electronic aerosol provision systems such as electronic cigarettes(e-cigarettes) generally contain an aerosol precursor material, such asa reservoir of a source liquid containing a formulation, typicallyincluding nicotine, or a solid material such a tobacco-based product,from which an aerosol is generated for inhalation by a user, for examplethrough heat vaporization. Thus, an aerosol provision system willtypically comprise a vaporizer, e.g. a heating element, arranged tovaporize a portion of precursor material to generate an aerosol in anaerosol generation region of an air channel through the aerosolprovision system. As a user inhales on the device and electrical poweris supplied to the vaporizer, air is drawn into the device through oneor more inlet holes and along the air channel to the aerosol generationregion, where the air mixes with the vaporised precursor material andforms a condensation aerosol. The air drawn through the aerosolgeneration region continues along the air channel to a mouthpieceopening, carrying some of the aerosol with it, and out through themouthpiece opening for inhalation by the user.

It is common for aerosol provision systems to comprise a modularassembly, often having two main functional parts, namely a control unitand disposable/replaceable cartridge part. Typically the cartridge partwill comprise the consumable aerosol precursor material and thevaporizer (atomiser), while the control unit part will compriselonger-life items, such as a rechargeable battery, device controlcircuitry, activation sensors and user interface features. The controlunit may also be referred to as a reusable part or battery section andthe replaceable cartridge may also be referred to as a disposable partor cartomizer.

The control unit and cartridge are mechanically coupled together at aninterface for use, for example using a screw thread, bayonet, latched orfriction fit fixing. When the aerosol precursor material in a cartridgehas been exhausted, or the user wishes to switch to a differentcartridge having a different aerosol precursor material, the cartridgemay be removed from the control unit and a replacement cartridge may beattached to the device in its place.

A potential drawbacks for cartridges containing liquid aerosol precursor(e-liquid) is the risk of leakage. An e-cigarette cartridge willtypically have a mechanism, e.g. a capillary wick, for drawingaerosolizable material from an aerosolizable material reservoir to avaporizer located in an air path/channel connecting from an air inlet toan aerosol outlet for the cartridge. Because there is a fluid transportpath from the aerosolizable material reservoir into the open air channelthrough the cartridge, there is a corresponding risk of aerosolizablematerial leaking from the cartridge. Leakage is undesirable both fromthe perspective of the end user naturally not wanting to get thee-liquid on their hands or other items, and also from a reliabilityperspective, since leakage from an end of the cartridge connected to thecontrol unit may damage the control unit, for example due to corrosion.Some approaches to reduce the risk of leakage may involve restrictingthe flow of aerosolizable material to the vaporizer, for example bytightly clamping a wick where it enters the air channel. In normal use,the aerosolizable material taken up by the wick is sufficient to keepthe vaporizer cool (i.e., at an ideal operating temperature), but whenthe aerosolizable material taken up is insufficient (e.g., when theaerosolizable material in the reservoir runs low) this can in somescenarios give rise to overheating and undesirable flavors.

Various approaches are therefore described herein which seek to helpaddress or mitigate some of the issues discussed above.

SUMMARY

According to a first aspect of certain embodiments there is provided anaerosol provision system comprising a reservoir for aerosolizablematerial; a wick configured to receive the aerosolizable material fromthe reservoir, a vaporizer configured to vaporize the aerosolizablematerial received in the wick, wherein the aerosol provision system isconfigured to measure at least one parameter of the wick to determine astatus of the wick.

According to a second aspect of certain embodiments there is provided acartridge for an aerosol provision system comprising the cartridge and acontrol unit, wherein the cartridge comprises:

-   -   a reservoir for aerosolizable material;    -   a wick configured to receive the aerosolizable material from the        reservoir; and    -   a vaporizer configured to vaporise the aerosolizable material        received in the wick,    -   wherein the cartridge is configured to measure at least one        parameter of the wick to determine a status of the wick.

According to a third aspect of certain embodiments there is provided anaerosolizable material for use in an aerosol provision system, whereinthe aerosolizable material comprises at least one doping agentcomprising a thermochromic material, wherein the thermochromic materialis configured to adopt a first color at a first predeterminedtemperature, and is configured to adopt a second color at a secondpredetermined temperature, wherein the second predetermined temperatureis higher than the first predetermined temperature.

According to a fourth aspect of certain embodiments there is provided acartridge for an aerosol provision system comprising the cartridge and acontrol unit, wherein the cartridge comprises:

-   -   an aerosolizable material transport element for receiving        aerosolizable material, and a vaporize configured to vaporize        the aerosolizable material received in the aerosolizable        material transport element, and    -   at least one doping agent which is configured to color the        aerosolizable material transport element a first color at a        first predetermined condition, and which is configured to color        the aerosolizable material transport element a second color,        which is different from the first color, at a second        predetermined condition which is different from the first        predetermined condition.

According to a fifth aspect of certain embodiments there is provided anaerosol provision system comprising an aerosolizable material transportelement for receiving aerosolizable material, and a vaporizer configuredto vaporize the aerosolizable material received in the aerosolizablematerial transport element;

-   -   wherein the aerosol provision system further comprises at least        one doping agent which is configured to color the aerosolizable        material transport element a first color at a first        predetermined condition, and which is configured to color the        aerosolizable material transport element a second color, which        is different from the first color, at a second predetermined        condition which is different from the first predetermined        condition.

According to a sixth aspect of certain embodiments there is provided anaerosolizable material transport element for receiving aerosolizablematerial, wherein the aerosolizable material transport element comprisesat least one doping agent which is configured to color the aerosolizablematerial transport element a first color at a first predeterminedcondition, and which is configured to color the aerosolizable materialtransport element a second color, which is different from the firstcolor, at a second predetermined condition which is different from thefirst predetermined condition.

According to a seventh aspect of certain embodiments there is provided amethod of indicating a change in condition of an aerosolizable materialtransport element which is configured to receive aerosolizable materialfrom a reservoir of aerosolizable material, wherein the methodcomprises:

-   -   coloring the aerosolizable material transport element a first        color at a first predetermined condition using a doping agent;        and    -   coloring the aerosolizable material transport element a second        color at a second predetermined condition, using the doping        agent, wherein the second predetermined condition is different        from the first predetermined condition.

According to an eighth aspect of certain embodiments there is providedan aerosol provision system comprising:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the aerosol provision system is configured to monitor at        least one parameter of the vaporizer, which is not the        electrical resistance of the heating element, to determine a        failure state of the aerosol provision system.

According to a ninth aspect of certain embodiments there is provided acartridge for an aerosol provision system comprising the cartridge and acontrol unit, wherein the cartridge comprises:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the cartridge is configured to monitor at least one        parameter of the vaporizer, which is not the electrical        resistance of the heating element, to determine a failure state        of the cartridge.

It will be appreciated that features and aspects of the inventiondescribed above in relation to the various aspects of the invention areequally applicable to, and may be combined with, embodiments of theinvention according to other aspects of the invention as appropriate,and not just in the specific combinations described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of exampleonly, with reference to the accompanying drawings, in which:

FIG. 1 schematically represents in perspective view an aerosol provisionsystem comprising a cartridge and control unit (shown separated) inaccordance with certain embodiments of the disclosure;

FIG. 2 schematically represents in exploded perspective view ofcomponents of the cartridge of the aerosol provision system of FIG. 1 ;

FIGS. 3A to 3C schematically represent various cross-section views of ahousing part of the cartridge of the aerosol provision system of FIG. 1;

FIGS. 4A and 4B schematically represent a perspective view and a planview of a dividing wall element of the cartridge of the aerosolprovision system of FIG. 1 ;

FIGS. 5A to 5C schematically represent two perspective views and a planview of a resilient plug of the cartridge of the aerosol provisionsystem of FIG. 1 ;

FIGS. 6A and 6B schematically represent a perspective view and a planview of a bottom cap of the cartridge of the aerosol provision system ofFIG. 1 ;

FIG. 7 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure;

FIG. 8 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure;

FIG. 9 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure;

FIG. 10 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure;

FIGS. 11A-11C represents schematic views of a portion of an aerosolprovision system in accordance with certain embodiments of thedisclosure;

FIG. 12 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure;

FIG. 13 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure; and

FIG. 14 represents a schematic view of an aerosol provision system inaccordance with certain embodiments of the disclosure.

DETAILED DESCRIPTION

Aspects and features of certain examples and embodiments arediscussed/described herein. Some aspects and features of certainexamples and embodiments may be implemented conventionally and these arenot discussed/described in detail in the interests of brevity. It willthus be appreciated that aspects and features of apparatus and methodsdiscussed herein which are not described in detail may be implemented inaccordance with any conventional techniques for implementing suchaspects and features.

The present disclosure relates to non-combustible aerosol provisionsystems, which may also be referred to as aerosol provision systems,such as e-cigarettes. According to the present disclosure, a“non-combustible” aerosol provision system is one where a constituentaerosolizable material of the aerosol provision system (or componentthereof) is not combusted or burned in order to facilitate delivery to auser. Aerosolizable material, which also may be referred to herein asaerosol generating material or aerosol precursor material, is materialthat is capable of generating aerosol, for example when heated,irradiated or energized in any other way.

Throughout the following description the term “e-cigarette” or“electronic cigarette” may sometimes be used, but it will be appreciatedthis term may be used interchangeably with aerosol provisionsystem/device and electronic aerosol provision system/device. Anelectronic cigarette may also known as a vaping device or electronicnicotine delivery system (END), although it is noted that the presenceof nicotine in the aerosolizable material is not a requirement.

In some embodiments, the non-combustible aerosol provision system is ahybrid system to generate aerosol using a combination of aerosolizablematerials, one or a plurality of which may be heated. In someembodiments, the hybrid system comprises a liquid or gel aerosolizablematerial and a solid aerosolizable material. The solid aerosolizablematerial may comprise, for example, tobacco or a non-tobacco product.

Typically, the non-combustible aerosol provision system may comprise anon-combustible aerosol provision device and an article for use with thenon-combustible aerosol provision device. However, it is envisaged thatarticles which themselves comprise a means for powering an aerosolgenerating component may themselves form the non-combustible aerosolprovision system.

In some embodiments, the article for use with the non-combustibleaerosol provision device may comprise an aerosolizable material (oraerosol precursor material), an aerosol generating component (orvaporizer), an aerosol generating area, a mouthpiece, and/or an area forreceiving aerosolizable material.

In some embodiments, the aerosol generating component is a heatercapable of interacting with the aerosolizable material so as to releaseone or more volatiles from the aerosolizable material to form anaerosol. In some embodiments, the aerosol generating component iscapable of generating an aerosol from the aerosolizable material withoutheating. For example, the aerosol generating component may be capable ofgenerating an aerosol from the aerosolizable material without applyingheat thereto, for example via one or more of vibrational, mechanical,pressurisation or electrostatic means.

In some embodiments, the substance to be delivered may be anaerosolizable material which may comprise an active constituent, acarrier constituent and optionally one or more other functionalconstituents.

The active constituent may comprise one or more physiologically and/orolfactory active constituents which are included in the aerosolizablematerial in order to achieve a physiological and/or olfactory responsein the user. The active constituent may for example be selected fromnutraceuticals, nootropics, and psychoactives. The active constituentmay be naturally occurring or synthetically obtained. The activeconstituent may comprise for example nicotine, caffeine, taurine,thiene, a vitamin such as B6 or B12 or C, melatonin, a cannabinoid, or aconstituent, derivative, or combinations thereof. The active constituentmay comprise a constituent, derivative or extract of tobacco or ofanother botanical. In some embodiments, the active constituent is aphysiologically active constituent and may be selected from nicotine,nicotine salts (e.g. nicotine ditartrate/nicotine bitartrate),nicotine-free tobacco substitutes, other alkaloids such as caffeine, ormixtures thereof.

In some embodiments, the active constituent is an olfactory activeconstituent and may be selected from a “flavor” and/or “flavorant”which, where local regulations permit, may be used to create a desiredtaste, aroma or other somatosensorial sensation in a product for adultconsumers. In some instances such constituents may be referred to asflavors, flavorants, cooling agents, heating agents, and/or sweeteningagents. They may include naturally occurring flavor materials,botanicals, extracts of botanicals, synthetically obtained materials, orcombinations thereof (e.g., tobacco, cannabis, licorice (liquorice),hydrangea, eugenol, Japanese white bark magnolia leaf, chamomile,fenugreek, clove, maple, matcha, menthol, Japanese mint, aniseed(anise), cinnamon, turmeric, Indian spices, Asian spices, herb,wintergreen, cherry, berry, red berry, cranberry, peach, apple, orange,mango, clementine, lemon, lime, tropical fruit, papaya, rhubarb, grape,durian, dragon fruit, cucumber, blueberry, mulberry, citrus fruits,Drambuie, bourbon, scotch, whiskey, gin, tequila, rum, spearmint,peppermint, lavender, aloe vera, cardamom, celery, cascarilla, nutmeg,sandalwood, bergamot, geranium, khat, naswar, betel, shisha, pine, honeyessence, rose oil, vanilla, lemon oil, orange oil, orange blossom,cherry blossom, cassia, caraway, cognac, jasmine, ylang-ylang, sage,fennel, wasabi, piment, ginger, coriander, coffee, hemp, a mint oil fromany species of the genus Mentha, eucalyptus, star anise, cocoa,lemongrass, rooibos, flax, Ginkgo biloba, hazel, hibiscus, laurel, mate,orange skin, rose, tea such as green tea or black tea, thyme, juniper,elderflower, basil, bay leaves, cumin, oregano, paprika, rosemary,saffron, lemon peel, mint, beefsteak plant, curcuma, cilantro, myrtle,cassis, valerian, pimento, mace, damien, marjoram, olive, lemon balm,lemon basil, chive, carvi, verbena, tarragon, limonene, thymol,camphene), flavor enhancers, bitterness receptor site blockers,sensorial receptor site activators or stimulators, sugars and/or sugarsubstitutes (e.g., sucralose, acesulfame potassium, aspartame,saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol,or mannitol), and other additives such as charcoal, chlorophyll,minerals, botanicals, or breath freshening agents.

They may be imitation, synthetic or natural ingredients or blendsthereof. They may be in any suitable form, for example, liquid such asan oil, solid such as a powder, or gasone or more of extracts (e.g.,licorice, hydrangea, Japanese white bark magnolia leaf, chamomile,fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb,wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch,whiskey, spearmint, peppermint, lavender, cardamom, celery, cascarilla,nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil,vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine,ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, ora mint oil from any species of the genus Mentha), flavor enhancers,bitterness receptor site blockers, sensorial receptor site activators orstimulators, sugars and/or sugar substitutes (e.g., sucralose,acesulfame potassium, aspartame, saccharine, cyclamates, lactose,sucrose, glucose, fructose, sorbitol, or mannitol), and other additivessuch as charcoal, chlorophyll, minerals, botanicals, or breathfreshening agents. They may be imitation, synthetic or naturalingredients or blends thereof. They may be in any suitable form, forexample, oil, liquid, or powder.

In some embodiments, the flavor comprises menthol, spearmint and/orpeppermint. In some embodiments, the flavour comprises flavourcomponents of cucumber, blueberry, citrus fruits and/or redberry. Insome embodiments, the flavor comprises eugenol. In some embodiments, theflavor comprises flavor components extracted from tobacco. In someembodiments, the flavor may comprise a sensate, which is intended toachieve a somatosensorial sensation which are usually chemically inducedand perceived by the stimulation of the fifth cranial nerve (trigeminalnerve), in addition to or in place of aroma or taste nerves, and thesemay include agents providing heating, cooling, tingling, numbing effect.A suitable heat effect agent may be, but is not limited to, vanillylethyl ether and a suitable cooling agent may be, but not limited toeucalyptol, WS-3.

The carrier constituent may comprise one or more constituents capable offorming an aerosol. In some embodiments, the carrier constituent maycomprise one or more of glycerine, glycerol, propylene glycol,diethylene glycol, triethylene glycol, tetraethylene glycol,1,3-butylene glycol, erythritol, meso-Erythritol, ethyl vanillate, ethyllaurate, a diethyl suberate, triethyl citrate, triacetin, a diacetinmixture, benzyl benzoate, benzyl phenyl acetate, tributyrin, laurylacetate, lauric acid, myristic acid, and propylene carbonate.

The one or more other functional constituents may comprise one or moreof pH regulators, coloring agents, preservatives, binders, fillers,stabilizers, and/or antioxidants.

As noted above, aerosol provision systems (e-cigarettes) often comprisea modular assembly including both a reusable part (control unit) and areplaceable (disposable) cartridge part. Devices conforming to this typeof two-part modular configuration may generally be referred to astwo-part devices. It is also common for electronic cigarettes to have agenerally elongate shape. For the sake of providing a concrete example,certain embodiments of the disclosure described herein comprise thiskind of generally elongate two-part device employing disposablecartridges. However, it will be appreciated the underlying principlesdescribed herein may equally be adopted for other electronic cigaretteconfigurations, for example modular devices comprising more than twoparts, as devices conforming to other overall shapes, for example basedon so-called box-mod high performance devices that typically have a moreboxy shape.

FIG. 1 is a schematic perspective view of an example aerosol provisionsystem/device (e-cigarette) 1 in accordance with certain embodiments ofthe disclosure. Terms concerning the relative location of variousaspects of the electronic cigarette (e.g. terms such as upper, lower,above, below, top, bottom etc.) are used herein with reference to theorientation of the electronic cigarette as shown in FIG. 1 (unless thecontext indicates otherwise). However, it will be appreciated this ispurely for ease of explanation and is not intended to indicate there isany required orientation for the electronic cigarette in use.

The e-cigarette 1 comprises two main components, namely a cartridge 2and a control unit 4. The control unit 4 and the cartridge 2 are shownseparated in FIG. 1 , but are coupled together when in use.

The cartridge 2 and control unit 4 are coupled by establishing amechanical and electrical connection between them. The specific mannerin which the mechanical and electrical connection is established is notof primary significance to the principles described herein and may beestablished in accordance with conventional techniques, for examplebased around a screw thread, bayonet, latched or friction-fit mechanicalfixing with appropriately arranged electrical contacts/electrodes forestablishing the electrical connection between the two parts asappropriate. For example electronic cigarette 1 represented in FIG. 1 ,the cartridge comprises a mouthpiece end 52 and an interface end 54 andis coupled to the control unit by inserting an interface end portion 6at the interface end of the cartridge into a corresponding receptacle8/cartridge receiving section of the control unit. The interface endportion 6 of the cartridge is a close fit to be receptacle 8 andincludes protrusions 56 which engage with corresponding detents in theinterior surface of a receptacle wall 12 defining the receptacle 8 toprovide a releasable mechanical engagement between the cartridge and thecontrol unit. An electrical connection is established between thecontrol unit and the cartridge via a pair of electrical contacts on thebottom of the cartridge (not shown in FIG. 1 ) and corresponding sprungcontact pins in the base of the receptacle 8 (not shown in FIG. 1 ).

As noted above, the specific manner in which the electrical connectionis established is not significant to the principles described herein,and indeed some implementations might not have an electrical connectionbetween the cartridge and a control unit at all, for example because thetransfer of electrical power from the reusable part to the cartridge maybe wireless (e.g. based on electromagnetic induction techniques).

The electronic cigarette 1 has a generally elongate shape extendingalong a longitudinal axis L. When the cartridge is coupled to thecontrol unit, the overall length of the electronic cigarette in thisexample (along the longitudinal axis) is around 12.5 cm. The overalllength of the control unit is around 9 cm and the overall length of thecartridge is around 5 cm (i.e. there is around 1.5 cm of overlap betweenthe interface end portion 6 of the cartridge and the receptacle 8 of thecontrol unit when they are coupled together). The electronic cigarettehas a cross-section which is generally oval and which is largest aroundthe middle of the electronic cigarette and tapers in a curved mannertowards the ends. The cross-section around the middle of the electroniccigarette has a width of around 2.5 cm and a thickness of around 1.7 cm.The end of the cartridge has a width of around 2 cm and a thickness ofaround 0.6 mm, whereas the other end of the electronic cigarette has awidth of around 2 cm and a thickness of around 1.2 cm. The outer housingof the electronic cigarette is in this example is formed from plastic.It will be appreciated the specific size and shape of the electroniccigarette and the material from which it is made is not of primarysignificance to the principles described herein and may be different indifferent implementations. That is to say, the principles describedherein may equally be adopted for electronic cigarettes having differentsizes, shapes and/or materials.

The control unit 4 may in accordance with certain embodiments of thedisclosure be broadly conventional in terms of its functionality andgeneral construction techniques. In the example of FIG. 1 , the controlunit 4 comprises a plastic outer housing 10 including the receptaclewall 12 that defines the receptacle 8 for receiving the end of thecartridge as noted above. The outer housing 10 of the control unit 4 inthis example has a generally oval cross section conforming to the shapeand size of the cartridge 2 at their interface to provide a smoothtransition between the two parts. The receptacle 8 and the end portion 6of the cartridge 2 are symmetric when rotated through 180° so thecartridge can be inserted into the control unit in two differentorientations. The receptacle wall 12 includes two control unit air inletopenings 14 (i.e. holes in the wall). These openings 14 are positionedto align with an air inlet 50 for the cartridge when the cartridge iscoupled to the control unit. A different one of the openings 14 alignswith the air inlet 50 of the cartridge in the different orientations. Itwill be appreciated some implementations may not have any degree ofrotational symmetry such that the cartridge is couplable to the controlunit in only one orientation while other implementations may have ahigher degree of rotational symmetry such that the cartridge iscouplable to the control unit in more orientations.

The control unit further comprises a battery 16 for providing operatingpower for the electronic cigarette, control circuitry 18 for controllingand monitoring the operation of the electronic cigarette, a user inputbutton 20, an indicator light 22, and a charging port 24.

The battery 16 in this example is rechargeable and may be of aconventional type, for example of the kind normally used in electroniccigarettes and other applications requiring provision of relatively highcurrents over relatively short periods. The battery 16 may be rechargedthrough the charging port 24, which may, for example, comprise a USBconnector.

The input button 20 in this example is a conventional mechanical button,for example comprising a sprung mounted component which may be pressedby a user to establish an electrical contact in underlying circuitry. Inthis regard, the input button may be considered an input device fordetecting user input, e.g. to trigger aerosol generation, and thespecific manner in which the button is implemented is not significant.For example, other forms of mechanical button or touch-sensitive button(e.g. based on capacitive or optical sensing techniques) may be used inother implementations, or there may be no button and the device may relyon a puff detector for triggering aerosol generation.

The indicator light 22 is provided to give a user with a visualindication of various characteristics associated with the electroniccigarette, for example, an indication of an operating state (e.g.on/off/standby), and other characteristics, such as battery life orfault conditions. Different characteristics may, for example, beindicated through different colors, and/or different flash sequences inaccordance with generally conventional techniques.

The control circuitry 18 is suitably configured/programmed to controlthe operation of the electronic cigarette to provide conventionaloperating functions in line with the established techniques forcontrolling electronic cigarettes. The control circuitry (processorcircuitry) 18 may be considered to logically comprise varioussub-units/circuitry elements associated with different aspects of theelectronic cigarette's operation. For example, depending on thefunctionality provided in different implementations, the controlcircuitry 18 may comprises power supply control circuitry forcontrolling the supply of power from the battery/power supply to thecartridge in response to user input, user programming circuitry forestablishing configuration settings (e.g. user-defined power settings)in response to user input, as well as other functional units/circuitryassociated functionality in accordance with the principles describedherein and conventional operating aspects of electronic cigarettes, suchas indicator light display driving circuitry and user input detectioncircuitry. It will be appreciated the functionality of the controlcircuitry 18 can be provided in various different ways, for exampleusing one or more suitably programmed programmable computer(s) and/orone or more suitably configured application-specific integratedcircuit(s)/circuitry/chip(s)/chipset(s) configured to provide thedesired functionality.

FIG. 2 is an exploded schematic perspective view of the cartridge 2(exploded along the longitudinal axis L). The cartridge 2 comprises ahousing part 32, an air channel seal 34, a dividing wall element 36, anoutlet tube 38, a vaporizer/heating element 40, an aerosolizablematerial transport element 42, a plug 44, and an end cap 48 with contactelectrodes 46. FIGS. 3 to 6 schematically represents some of thesecomponents in more detail.

FIG. 3A is a schematic cut-away view of the housing part 32 through thelongitudinal axis L where the housing part 32 is thinnest. FIG. 3B is aschematic cut-away view of the housing part 32 through the longitudinalaxis L where the housing part 32 is widest. FIG. 3C is a schematic viewof the housing part along the longitudinal axis L from the interface end54 (i.e. viewed from below in the orientation of FIGS. 3A and 3B).

FIG. 4A is a schematic perspective view of the dividing wall element 36as seen from below. FIG. 4B is a schematic cross-section through anupper part of the dividing wall element 36 as viewed from below.

FIG. 5A is a schematic perspective view of the plug 44 from above andFIG. 5B is a schematic perspective view of the plug 44 from below. FIG.5C is a schematic view of the plug 44 along the longitudinal axis L seenfrom the mouthpiece end 52 of the cartridge (i.e. viewed from above forthe orientation in FIGS. 1 and 2 ).

FIG. 6A is a schematic perspective view of the end cap 48 from above.FIG. 6B is a schematic view of the end cap 48 along the longitudinalaxis L seen from the mouthpiece end 52 of the cartridge (i.e. fromabove).

The housing part 32 in this example comprises a housing outer wall 64and a housing inner tube 62 which in this example are formed from asingle moulding of polypropylene. The housing outer wall 64 defines theexternal appearance of the cartridge 2 and the housing inner tube 62defines a part the air channel through the cartridge. The housing partis open at the interface end 54 of the cartridge and closed at themouthpiece end 52 of the cartridge except for a mouthpieceopening/aerosol outlet 60 in fluid communication with the housing innertube 62. The housing part 32 includes an opening in a sidewall whichprovides the air inlet 50 for the cartridge. The air inlet 50 in thisexample has an area of around 2 mm². The outer surface of the outer wall64 of the housing part 32 includes the protrusions 56 discussed abovewhich engage with corresponding detents in the interior surface of thereceptacle wall 12 defining the receptacle 8 to provide a releasablemechanical engagement between the cartridge and the control unit. Theinner surface of the outer wall 64 of the housing part includes furtherprotrusions 66 which act to provide an abutment stop for locating thedividing wall element 36 along the longitudinal axis L when thecartridge is assembled. The outer wall 64 of the housing part 32 furthercomprises holes which provide latch recesses 68 arranged to receivecorresponding latch projections 70 in the end cap to fix the end cap tobe housing part when the cartridge is assembled.

The outer wall 64 of the housing part 32 includes a double-walledsection 74 that defines a gap 76 in fluid communication with the airinlet 50. The gap 76 provides a portion of the air channel through thecartridge. In this example the doubled-walled section 74 of the housingpart 32 is arranged so the gap defines an air channel running within thehousing outer wall 64 parallel to the longitudinal axis with across-section in a plane perpendicular to the longitudinal axis ofaround 3 mm². The gap/portion of air channel 76 defined by thedouble-walled section of the housing part extends down to the open endof the housing part 32.

The air channel seal 34 is a silicone moulding generally in the form ofa tube having a through hole 80. The outer wall of the air channel seal34 includes circumferential ridges 84 and an upper collar 82. The innerwall of the air channel seal 34 also includes circumferential ridges,but these are not visible in FIG. 2 . When the cartridge is assembledthe air channel seal 34 is mounted to the housing inner tube 62 with anend of the housing inner tube 62 extending partly into the through hole80 of the air channel seal 34. The through hole 80 in the air channelseal has a diameter of around 5.8 mm in its relaxed state whereas theend of the housing inner tube 62 has a diameter of around 6.2 mm so thata seal is formed when the air channel seal 34 is stretched toaccommodate the housing inner tube 62. This seal is facilitated by theridges on the inner surface of the air channel seal 34.

The outlet tube 38 comprises a tubular section of ANSI 304 stainlesssteel with an internal diameter of around 8.6 mm and a wall thickness ofaround 0.2 mm. The bottom end of the outlet tube 38 includes a pair ofdiametrically opposing slots 88 with an end of each slot having asemi-circular recess 90. When the cartridge is assembled the outlet tube38 mounts to the outer surface of the air channel seal 34. The outerdiameter of the air channel seal is around 9.0 mm in its relaxed stateso that a seal is formed when the air channel seal 34 is compressed tofit inside the outlet tube 38. This seal is facilitated by the ridges 84on the outer surface of the air channel seal 34. The collar 80 on theair channel seal 34 provides a stop for the outlet tube 38.

The aerosolizable material transport element 42 comprises a capillarywick and the vaporizer 40 comprises a resistance wire heater woundaround the capillary wick. In addition to the portion of the resistancewire wound around the capillary wick, the vaporizer comprises electricalleads 41 which pass through holes in the plug 44 to contact electrodes46 mounted to the end cap 54 to allow power to be supplied to thevaporizer via the electrical interface the established when thecartridge is connected to a control unit. The vaporizer leads 41 maycomprise the same material as the resistance wire wound around thecapillary wick, or may comprise a different material (e.g.lower-resistance material) connected to the resistance wire wound aroundthe capillary wick. In this example the heater coil 40 comprises anickel iron alloy wire and the wick 42 comprises a glass fibre bundle.The vaporizer and aerosolizable material transport element may beprovided in accordance with any conventional techniques and is maycomprise different forms and/or different materials. For example, insome implementations the wick may comprise fibrous or solid a ceramicmaterial and the heater may comprise a different alloy. In otherexamples the heater and wick may be combined, for example in the form ofa porous and a resistive material. More generally, it will beappreciated the specific nature aerosolizable material transport elementand vaporizer is not of primary significance to the principles describedherein.

When the cartridge is assembled, the wick 42 is received in thesemi-circular recesses 90 of the outlet tube 38 so that a centralportion of the wick about which the heating coil is would is inside theoutlet tube while end portions of the wick are outside the outlet tube38.

The plug 44 in this example comprises a single moulding of silicone, maybe resilient. The plug comprises a base part 100 with an outer wall 102extending upwardly therefrom (i.e. towards the mouthpiece end of thecartridge). The plug further comprises an inner wall 104 extendingupwardly from the base part 100 and surrounding a through hole 106through the base part 100.

The outer wall 102 of the plug 44 conforms to an inner surface of thehousing part 32 so that when the cartridge is assembled the plug in 44forms a seal with the housing part 32. The inner wall 104 of the plug 44conforms to an inner surface of the outlet tube 38 so that when thecartridge is assembled the plug 44 also forms a seal with the outlettube 38. The inner wall 104 includes a pair of diametrically opposingslots 108 with the end of each slot having a semi-circular recess 110.Extended outwardly (i.e. in a direction away from the longitudinal axisof the cartridge) from the bottom of each slot in the inner wall 104 isa cradle section 112 shaped to receive a section of the aerosolizablematerial transport element 42 when the cartridge is assembled. The slots108 and semi-circular recesses 110 provided by the inner wall of theplug 44 and the slots 88 and semi-circular recesses 90 of the outlettube 38 are aligned so that the slots 88 in the outlet tube 38accommodate respective ones of the cradles 112 with the respectivesemi-circular recesses in the outlet tube and plug cooperating to defineholes through which the aerosolizable material transport element passes.The size of the holes provided by the semi-circular recesses throughwhich the aerosolizable material transport element passes correspondclosely to the size and shape of the aerosolizable material transportelement, but are slightly smaller so a degree of compression is providedby the resilience of the plug 44. This allows aerosolizable material tobe transported along the aerosolizable material transport element bycapillary action while restricting the extent to which aerosolizablematerial which is not transported by capillary action can pass throughthe openings. As noted above, the plug 44 includes further openings 114in the base part 100 through which the contact leads 41 for thevaporizer pass when the cartridge is assembled. The bottom of the basepart of the plug includes spacers 116 which maintain an offset betweenthe remaining surface of the bottom of the base part and the end cap 48.These spacers 116 include the openings 114 through which the electricalcontact leads 41 for the vaporizer pass.

The end cap 48 comprises a polypropylene moulding with a pair ofgold-plated copper electrode posts 46 mounted therein.

The ends of the electrode posts 44 on the bottom side of the end cap areclose to flush with the interface end 54 of the cartridge provided bythe end cap 48. These are the parts of the electrodes to whichcorrespondingly aligned sprung contacts in the control unit connect whenthe cartridge is assembled and connected to the control unit. The endsof the electrode posts on the inside of the cartridge extend away fromthe end cap 48 and into the holes 114 in the plug 44 through which thecontact leads 41 pass. The electrode posts are slightly oversizedrelative to the holes 114 and include a chamfer at their upper ends tofacilitate insertion into the holes 114 in the plug where they aremaintained in pressed contact with the contact leads for the vaporizerby virtue of the plug.

The end cap has a base section 124 and an upstanding wall 120 whichconforms to the inner surface of the housing part 32. The upstandingwall 120 of the end cap 48 is inserted into the housing part 32 so thelatch projections 70 engage with the latch recesses 68 in the housingpart 32 to snap-fit the end cap 48 to the housing part when thecartridge is assembled. The top of the upstanding wall 120 of the endcap 48 abuts a peripheral part of the plug 44 and the lower face of thespacers 116 on the plug also abut the base section 124 of the plug sothat when the end cap 48 is attached to the housing part it pressesagainst the resilient part 44 to maintain it in slight compression.

The base portion 124 of the end cap 48 includes a peripheral lip 126beyond the base of the upstanding wall 112 with a thickness whichcorresponds with the thickness of the outer wall of the housing part atthe interface end of the cartridge. The end cap also includes anupstanding locating pin 122 which aligns with a corresponding locatinghole 128 in the plug to help establish their relative location duringassembly.

The dividing wall element 36 comprises a single moulding ofpolypropylene and includes a dividing wall 130 and a collar 132 formedby projections from the dividing wall 130 in the direction towards theinterface end of the cartridge. The dividing wall element 36 has acentral opening 134 through which the outlet tube 38 passes (i.e. thedividing wall is arranged around the outlet tube 38). When the cartridgeis assembled, the upper surface of the outer wall 102 of the plug 44engages with the lower surface of the dividing wall 130, and the uppersurface of the dividing wall 130 in turn engages with the projections 66on the inner surface of the outer wall 64 of the housing part 32. Thus,the dividing wall 130 prevents the plug from being pushed too far intothe housing part 32—i.e. the dividing wall 130 is fixedly located alongthe longitudinal axis of the cartridge by the protrusions 66 in thehousing part and so provides the plug with a fixed surface to pushagainst. The collar 132 formed by projections from the dividing wallincludes a first pair of opposing projections/tongues 134 which engagewith corresponding recesses on an inner surface of the outer wall 102 ofthe plug 44. The protrusions from the dividing wall 130 further providea pair of cradle sections 136 configured to engage with correspondingones of the cradle sections 112 in the part 44 when the cartridge isassembled to further define the opening through which the aerosolizablematerial transport element passes.

When the cartridge is assembled an air channel extending from the airinlet 50 to the aerosol outlet 60 through the cartridge is formed.Starting from the air inlet 50 in the side wall of the housing part 32,a first section of the air channel is provided by the gap 76 formed bythe double-walled section 74 in the outer wall 64 of the housing part 32and extends from the air inlet 50 towards the interface end 54 of thecartridge and past the plug 44. A second portion of the air channel isprovided by the gap between the base of the plug 44 and the end cap 48.A third portion of the air channel is provided by the hole 106 throughthe plug 44. A fourth portion of the air channel is provided by theregion within the inner wall 104 of the plug and the outlet tube aroundthe vaporizer 40. This fourth portion of the air channel may also bereferred to as an aerosol/aerosol generation region, it being theprimary region in which aerosol is generated during use. The air channelfrom the air inlet 50 to the aerosol generation region may be referredto as an air inlet section of the air channel. A fifth portion of theair channel is provided by the remainder of the outlet tube 38. A sixthportion of the air channel is provided by the outer housing inner tube62 which connects the air channel to the aerosol outlet 60. The airchannel from the aerosol generation region to be the aerosol outlet maybe referred to as an aerosol outlet section of the air channel.

Also, when the cartridge is assembled a reservoir 31 for aerosolizablematerial is formed by the space outside the air channel and inside thehousing part 32. This may be filled during manufacture, for examplethrough a filling hole which is then sealed, or by other means. Thespecific nature of the aerosolizable material, for example in terms ofits composition, is not of primary significance to the principlesdescribed herein, and in general any conventional aerosolizable materialof the type normally used in electronic cigarettes may be used. Thepresent disclosure may refer to a liquid as the aerosolizable material,which as mentioned above may be a conventional e-liquid. However, theprinciples of the present disclosure apply to any aerosolizable materialwhich has the ability to flow, and may include a liquid, a gel, or asolid, where for a solid a plurality of solid particles may beconsidered to have the ability to flow when considered as a bulk.

The reservoir is closed at the interface end of the cartridge by theplug 44. The reservoir includes a first region above the dividing wall130 and a second region below the dividing wall 130 within the spaceformed between the air channel and the outer wall of the plug. Theaerosolizable material transport element (capillary wick) 42 passesthrough openings in the wall of the air channel provided by thesemi-circular recesses 108, 90 in the plug 44 and the outlet tube 38 andthe cradle sections 112, 136 in the plug 44 and the dividing wallelement 36 that engage with one another as discussed above. Thus, theends of the aerosolizable material transport element extend into thesecond region of the reservoir from which they draw aerosolizablematerial through the openings in the air channel to the vaporizer 40 forsubsequent vaporisation.

In normal use, the cartridge 2 is coupled to the control unit 4 and thecontrol unit activated to supply power to the cartridge via the contactelectrodes 46 in the end cap 48. Power then passes through theconnection leads 41 to the vaporizer 40. The vaporizer is thuselectrically heated and so vaporises a portion of the aerosolizablematerial from the aerosolizable material transport element in thevicinity of the vaporizer. This generates aerosol in the aerosolgeneration region of the air path. Aerosolizable material that isvaporised from the aerosolizable material transport element is replacedby more aerosolizable material drawn from the reservoir by capillaryaction. While the vaporizer is activated, a user inhales on themouthpiece end 52 of the cartridge. This causes air to be drawn throughwhichever control unit air inlet 14 aligns with the air inlet 50 of thecartridge (which will depend on the orientation in which the cartridgewas inserted into the control unit receptacle 8). Air then enters thecartridge through the air inlet 50, passes along the gap 76 in thedouble-walled section 74 of the housing part 32, passes between the plug44 and the end cap 48 before entering the aerosol generation regionsurrounding the vaporizer 40 through the hole 106 in the base part 100of the plug 44. The incoming air mixes with aerosol generated from thevaporizer to form a condensation aerosol, which is then drawn along theoutlet tube 38 and the housing part inner 62 before exiting through themouthpiece outlet/aerosol outlet 60 for user inhalation.

With reference to FIGS. 7-10 and 12 , there is shown schematically across section view of a modified cartridge 2 for use with a control unit4 to form an aerosol provision system 1 in accordance with certainembodiments of the disclosure. The aerosol provision system 1; cartridge2; and control unit 4 shown in FIGS. 7-10 and 12 are based on theconstruction of the corresponding aerosol provision system 1; cartridge2; and control unit 4; shown in FIGS. 1-6B, and comprise similarcomponents as set out by the reference numerals that are common to bothsets of Figures. For instance, the cartridge 2 defines a reservoir 31which extends around an aerosol outlet tube 38. In accordance with suchembodiments, the reservoir 31 may be annular, and is configured forcontaining aerosolizable material for aerosolising. Similarly, thecontrol unit 4 may comprise the plastic outer housing 10 including thereceptacle wall 12 that defines the receptacle 8 for receiving the endof the cartridge 2. The control unit 4 may also comprise the controlcircuitry 18 and the power supply/battery 16.

Noting the above, and with initial reference to the aerosol provisionsystem 1 shown in FIG. 7 , a first modification over the aerosolprovision system shown 1 in FIGS. 1-6B is the introduction of aconfiguration to measure at least one parameter of the wick to determinea status of the wick. In essence therefore, and at a broad level, FIG. 7illustrates an aerosol provision system 1 comprising a reservoir 31 foraerosolizable material; a wick 42 configured to receive theaerosolizable material from the reservoir 31, a vaporizer 40 configuredto vaporise the aerosolizable material received in the wick 42, whereinthe aerosol provision system 1 is configured to measure at least oneparameter of the wick 42 to determine a status of the wick 42.

In principal, this status of the wick 42 (or aerosolizable materialtransport element 42) could relate to variety of different statuses forthe aerosolizable material transport element/wick 42. However, inaccordance with some particular embodiments, the status may be the wickcontaining 42 less than a predetermined amount of aerosolizablematerial, and/or the wick exceeding a predetermined temperature. Boththese may therefore correspond to a dry-out status of the wick 42,whereby the wick 42 is not saturated with aerosolizable material. Duringsuch dry-out conditions, as the vaporizer 40 is operated, this may causethe wick 42 to become excessively hot, as a result of the heat generatedby the vaporizer 40, and as result of there not being sufficientaerosolizable material to help cool the temperature of the wick 42.

In such a dry-out status, in so far as the aerosol provision system 1 isconfigured to measure at least one parameter of the wick 42 to determinea status of the wick 42, this may allow the aerosol provision system 1to react in such instances where a dry-out status is detected, as willbe described.

In that respect, and in accordance with some embodiments, the aerosolprovision system 1 may be provided with the control circuitry 18, and atleast one sensor 200 for detecting the at least one parameter. In suchembodiments, each sensor 200 is configured to output a sensor signalcontaining data related to the at least one parameter. In this way, thecontrol circuitry 18 may be then configured to process the data from thesensor signal of each sensor 200 to determine the status of the wick 42.

It is envisaged herein that the type of sensor(s) 200 used will dependon the parameter which the sensor 200 is configured to detect.

In that respect therefore, in accordance with some embodiments, and withreference to FIG. 7 , the at least one parameter may comprise themoisture content of the wick 42, wherein the at least one sensor 200comprises at least one load cell 202 on which the wick 42 is supported.In this embodiment, each load cell 202 may be configured to output asensor signal containing mass data related to the mass of the wick 42.The control circuitry 18 may be then further configured to process themass data from the sensor signal of each load cell 200 to determine amass value for the wick 42, and then compare the mass value for the wickagainst a predetermined mass value. In this embodiment therefore, as thewick becomes wet/saturated in use with aerosolizable material, the massof the wick 42 will vary depending on the quantity of aerosolizablematerial therein. Noting each load cell 200 supports the wick 42, eachload cell 202 may be therefore configured to output the sensor signalcontaining mass data related to the mass of the wick 42. In respect ofthe predetermined mass value, this in accordance with some embodimentsmay be selected to correspond to the mass of the wick at the cusp of adry-out status, whereby an insufficient amount of aerosolizable materialis contained in the wick 42 and/or whereby the wick 42 is not saturatedwith aerosolizable material.

Accordingly, in the event the mass value is less than the predeterminedmass value, the control circuitry 18 may be then configured to output acontrol signal, e.g. to affect/control the subsequent working of theaerosol provision system 1. In that respect, and in accordance with someembodiments, the control signal may comprise a command to disable theoperation of the aerosol provision system 1 and/or a command to disablethe operation of the vaporizer 40. In some particular embodimentsthereof, the control circuitry 18 may be then configured to disable theoperation of the aerosol provision system 1 and/or the vaporizer 40until the control circuitry 18 determines that a different cartridge 2has been coupled to the control unit 4, or until the control circuitry18 subsequently determines a mass value for the wick as being more thanthe predetermined mass value.

In accordance with some embodiments, the control signal may comprise acommand to provide a notification to a user. In accordance with someembodiments thereof, the control signal may comprise at least one of: anoptical signal, an acoustic signal, and a haptic signal, which can beused to provide a notification to the user. Such a notification, inaccordance with some particular embodiments, may include any of: anotification to the user that the aerosolizable material requiresrefilling; that the cartridge 2 requires replacing (where a cartridge2/control unit 4 arrangement is employed); and/or a notification to theuser that at least a portion of the aerosol provision system 1 hasoverheated.

To implement the above indications, as required, in accordance with someembodiments, the aerosol provision system 1 may further comprise any oneor combination of an optic element (such as an LED), an acoustic element(such as a speaker) and a haptic feedback element (such as a vibrator).Appreciably, in some particular embodiments to those set out above, anysuch optical/acoustic/haptic feedback element(s) may be mostconveniently located on the control unit 4 (where such a cartridge2/control unit 4 arrangement is employed).

Whatever the control signal that may be employed, in the embodimentswhere at least one cell 202 is provided, in accordance with someembodiments thereof, to better support the wick 42, and to allow for amore accurate mass value to be determined, in accordance with someembodiments (such as that shown in FIG. 7 ), the at least one load cell202 may comprise a first load cell 202A which supports a first end 42Aof the wick 42, and a second load cell 202B which supports a second end42A of the wick 42.

Aside from the possible use of a load cell(s) 202 in the context of theparameter being the moisture content of the wick 42, in accordance withsome embodiments, the at least one parameter mayadditionally/alternatively comprises at least one physical dimension ofthe wick, and wherein the at least one sensor 200 comprise a dimensionsensor 204 for detecting the at least one physical dimension of the wick204. In such embodiments, the dimension sensor 204 (as shown in FIG. 8or 9 , for instance) is configured to output a sensor signal containingdimension data related to the at least one physical dimension of thewick 42, such that the control circuitry 18 is configured to process thedimension data from the sensor signal of the dimension sensor 204 todetermine a dimension value for the wick 42, and then compare thedimension value for the wick 42 against a predetermined dimension value.In this embodiment therefore, as the wick becomes wet/saturated in usewith aerosolizable material, the physical dimensions of the wick 42 willvary depending on the quantity of aerosolizable material therein (inother words, the physical dimensions of the wick 42 will slightlyswell/contract depending on the quantity of aerosolizable materialtherein). That being the case, each dimension sensor(s) 204 may betherefore configured to output the sensor signal containing dimensiondata related to the at least one physical dimension of the wick 42. Inrespect of the predetermined dimension value, this in accordance withsome embodiments may be selected to correspond to a dimension value ofthe wick at the cusp of a dry-out status, whereby an insufficient amountof aerosolizable material is contained in the wick 42 and/or whereby thewick 42 is not saturated with aerosolizable material (i.e. in a statewhere the dimension value is sufficiently reduced as a result of therebeing an insufficient amount of aerosolizable material in the wick 42).

Accordingly, in the event the dimension value is less than thepredetermined dimension value, the control circuitry 18 may then beconfigured to output a control signal, e.g. to affect/control thesubsequent working of the aerosol provision system 1. Such a controlsignal in accordance with some particular embodiments thereof, asexplained previously in respect of FIG. 7 , could provide a notificationto the user and/or comprise a command to disable the operation of all,or at least a part of, the aerosol provision system 1.

With regard to what the physical dimension of the wick 42 mightexpressly be, it will be appreciated that this physical dimension couldbe any dimension whose quantity will change as the wick 42 starts to dryout. In that respect therefore, and in accordance with some embodiments,the at least one physical dimension may comprise the length L of thewick, wherein the length L extends from the first end 42A to the secondend 42B of the wick 42, and wherein the dimension data is related to thelength L of the wick. Such a psychical dimension may be detected in thearrangement shown in FIG. 9 , where the dimension sensor 204 inaccordance with some embodiments may comprise at least one laser measuresensor located at the first and second ends 42A;42B of the wick 42. Inthat respect however, it will be entirely appreciated that any othertype of dimension sensor(s) may be used/positioned in the aerosolprovision system 1 to measure the length L of the wick 42, and which maybe a contact sensor and/or a non-contact sensor, as required.

In accordance with some embodiments, the at least one physical dimensionmay comprise a width of the wick 42, wherein the dimension data isrelated to the width of the wick (as shown in the arrangement FIG. 8 ).Again, in accordance with some of these embodiments, the dimensionsensor 204 may comprise at least one laser measure sensor appropriatelylocated with respect to the wick 42 such to determine the width of thewick 42. And in that respect again, it will be entirely appreciated thatany other type of dimension sensor(s) may be used/positioned in theaerosol provision system 1 in such embodiments to appropriately measurethe width of the wick 42.

Where the dimension data is related to the width of the wick 42, inaccordance with some embodiments thereof, such as that shown in FIG. 8 ,the width may corresponds to a width of the wick 42 which is locatedbetween the first end 42A and the second end 42B of the wick 42, whereinthe wick is configured to receive the aerosolizable material at thefirst end 42A and the second end of the wick 42B. In such embodiments,the width in some particular embodiments thereof may be convenientlylocated at the midpoint along the length L of the wick (such as in FIG.8 ). In such arrangements, by measuring the parameter (in this case, thewidth) at a position from the wick 42 which is between the locationswhere the aerosolizable material is configured to be received in thewick 42, or put differently which is in a position from the wick 42which is most distal from one or all of the locations where theaerosolizable material is configured to be received in the wick 42, themeasured parameter may correspond to a position of the wick 42 where adry-out status is first likely to occur. In which case, such a positionfor the measured parameter may allow the aerosol provision system 1 todetermine a (dry-out) status of the wick quicker.

Aside from the possible use of a dimension sensor 204 in the context ofthe parameter being at least one physical dimension of the wick, inaccordance with some embodiments, the at least one parameter mayadditionally/alternatively comprise an optical parameter, wherein the atleast one sensor comprises an optical sensor 206, as shown in FIGS. 10an 12. In accordance with such embodiments, the optical sensor 206 maybe configured to output a sensor signal containing data related to theoptical parameter. In accordance with such embodiments, the controlcircuitry 18 may be further configured to process the data from thesensor signal of each optical sensor 206 to determine an optical valuefor the wick, and from there compare the optical value for the wickagainst a predetermined optical value.

With reference to the terms optical parameter and optical value, theseare intended to cover any measureable optical property of the wick whichis configured to change as the wick becomes hot/cool, and/or as thelevel of aerosolizable material in the wick changes. In that respecttherefore, and in accordance with some non-limiting embodiments, theoptical parameter may comprise the color of at least a portion 208 ofthe wick 42, and/or may comprise the reflectivity a portion of at leasta portion 208 of the wick 42. In accordance with some particularembodiments thereof, such a portion 208 may correspond to an externalsurface of the wick 42. In a very particular embodiment thereof, and forthe reasons explained previously, the external surface of the wick maybe located between the first end 42A and the second end 42B of the wick42 at which the wick 42 is configured to receive the aerosolizablematerial. And in such embodiments, to facilitate the aerosol provisionsystem 1 being able to determine a (dry-out) status of the wick quicker,the portion/external surface of the wick 42 may be conveniently locatedat any of: the midpoint along the length L of the wick 42; a positionfrom the wick 42 which is between the locations where the aerosolizablematerial is configured to be received in the wick 42; and/or in aposition from the wick 42 which is most distal from one or all of thelocations where the aerosolizable material is configured to be receivedin the wick 42.

In accordance with the above embodiment therefore, as the wick 42(aerosolizable material transport element) 42 is cool and/or iswet/saturated in use with aerosolizable material, the optical value ofthe wick 42 will vary. In that respect, where the wick 42 starts tobecome excessively hot and/or dry, the wick 42 may begin to discolorand/or exhibit a change in color or reflectance caused by the excessheat or dryness, which can be measured by the optical sensor(s) 206 andoutput as part of the sensor signal to the control circuitry 18. Withreference to FIGS. 11A-11C, such a change in color (or reflectance) ofthe wick is visualised. In that respect, with reference to FIGS.11A-11C, there is shown a portion of an aerosol provision system 1,including an optical sensor 206 configured to output a sensor signalcontaining data related to the optical parameter of the wick 42.

In the above respect, and considering first the operation of FIG. 11A,in this operation the wick 42 may be configured to be operating in asufficiently cool and/or wet configuration, wherein the wick issaturated with aerosolizable material that is supplied to the wick 42(shown in FIG. 11A as aerosolizable material ingress points AM_(in),which are located at the first end 42A and the second end 42B of thewick 42).

In operations where the wick 42 starts to become excessively hot and/drythrough the wick 42 no longer being saturated with aerosolizablematerial (i.e. a dry-out status) via the aerosolizable material ingresspoints AM_(in), the optical parameter (such as the color of the portion208 of the wick 42, and/or the reflectivity of the portion 208 the wick42) of the wick 42 may begin to change. In that respect for instance, inFIG. 11B, there is shown only the portion 208 of the wick 42 changingcolor/reflectance as a result of it becoming sufficiently hot and dry.

As the dry-out status continues to further manifest itself, the resultmay be that shown in FIG. 11C, which shows the entirety of the wick 42changing color/reflectance as a result of it becoming sufficiently hotand dry.

From the foregoing therefore, for a given wick (aerosolizable materialtransport element) 42, each optical sensor 208 may be configured tooutput a sensor signal containing data related to the optical parameterbeing sensed (such as the color and/or reflectance of the portion 208 ofthe wick 42 as shown in FIGS. 10 and 12 , and FIGS. 11A-11C), and suchthat the control circuitry 18 may be configured to process the data fromthe sensor signal of each optical sensor 206 to determine an opticalvalue for the wick 42. From there, the control circuitry 18 may be thenconfigured to compare the optical value for the wick against apredetermined optical value; and finally output a control signal in theevent the optical value is greater than, and/or less than, apredetermined optical value. Put differently, the control signal mightbe configured to output the control signal in the event the opticalvalue is indicative of a (dry-out) status of the wick.

In the above respect, the predetermined optical value may notionallycorrespond to an optical value where the wick is in a dry-out status,whereby an insufficient amount of aerosolizable material is contained inthe wick 42 and/or whereby the wick 42 is not saturated withaerosolizable material (as shown for instance, in either FIG. 11B or11C).

In that respect as well, whether the optical value should be greaterthan, and/or less than, the predetermined optical value will notionallydepend on the particular optical parameter being measured by the opticalsensor(s) 206, and what the optical value is (such as the optical valuecomprising a set of Red, Green, and Blue values; the optical valuecomprising a light reflectance value; and/or the optical valuecomprising a lumen value; and/or the optical value comprising a luxvalue).

Whatever the optical value used, and whatever the optical parameterbeing measured, in the event the control circuitry 18 determines theoptical value as being indicative of the status of the wick, the controlcircuitry 18 may then be configured to output a control signal, e.g. toaffect/control the subsequent working of the aerosol provision system 1.Such a control signal in accordance with some particular embodimentsthereof, as explained previously in respect of FIG. 7 , could forinstance provide a notification to the user and/or comprise a command todisable the operation of all, or at least a part of, the aerosolprovision system 1.

From the foregoing therefore, it can be seen that there may be providedan aerosol provision system 1 comprising a reservoir 31 foraerosolizable material; a wick (aerosolizable material transportelement) 42 configured to receive the aerosolizable material from thereservoir 31, a vaporizer 40 configured to vaporise the aerosolizablematerial received in the wick 42, wherein the aerosol provision system 1is configured to measure at least one parameter of the wick to determinea status of the wick, such as (but not necessarily limited to) a dry-outstatus.

In respect of any such operation of the aerosol provision system 1 todetermine the status of the wick, it is envisaged that this operationmay be implemented in any of the aerosol provision systems 1 describedherein, such as those disclosed in FIGS. 1-6B, and which comprise thecartridge 2 and a control unit 4. In accordance with such embodiments,the reservoir 31 may be located in the cartridge, and wherein thecontrol unit 4 comprises the cartridge receiving section 8 that includesan interface arranged to cooperatively engage with the cartridge 2 so asto releasably couple the cartridge 2 to the control unit 4, wherein thecontrol unit further comprises the power supply 16 for delivering powerto the vaporizer 40.

Where a cartridge 2 and control unit 4 is employed in the aerosolprovision system 1, in accordance with such embodiments any providedcontrol circuitry 18 may be located in either the control unit 4 and/orthe cartridge 2.

In the above respect as well, it is envisaged that any determining ofthe status of the wick may in accordance with some embodiments beperformed by the cartridge 2. In which case, in such embodiments, theremay be effectively provided a cartridge 2 for an aerosol provisionsystem 1 comprising the cartridge 2 and a control unit 4, wherein thecartridge comprises: the reservoir 31 for aerosolizable material; thewick 42 configured to receive the aerosolizable material from thereservoir 31; and the vaporizer 40 configured to vaporise theaerosolizable material received in the wick 42, wherein the cartridge 2is configured to measure at least one parameter of the wick 42 todetermine a status of the wick 42.

Conscious of the above embodiments which employ a cartridge 2 and acontrol unit 4, for the avoidance of any doubt, the aerosol provisionsystems 1 described herein may be equally applicable in otherembodiments which do not employ a cartridge 2 which is configured to bereceived in a control unit 4.

In respect of the wick/aerosolizable material transport elementarrangements shown in FIGS. 7-12 , the vaporizer 40 is shown asextending around the wick/aerosolizable material transport element 40,though it will be appreciated that the teachings herein described may beapplicable to other arrangements of wick 42 and/or vaporizer 40. In thatrespect for instance, it will be appreciated that the teachings hereinmay be applicable to other types of wick 42, such as where the wick 42comprises a ceramic wick. In accordance with such embodiments, thevaporizer 40 may comprise a conductive material located on an externalsurface of the wick 42. Such conductive material may appreciably takeany required shape on the surface of the wick 42, e.g. a spiral pattern;a raster pattern; or a zig-zag pattern such to allow the vaporizer 40 toefficiently vaporise the aerosolizable material in the wick 42. As willbe appreciated, the conductive material may be connected to theconnection leads 41 which deliver power to the vaporizer 40, as is alsothe case for the embodiments shown in FIGS. 7-12 where the vaporizer 40may be similarly connected to the connection leads 41.

For the sake of completeness therefore, whilst the vaporizer 40 inaccordance with some embodiments may be configured to extend around thewick 42, and/or be located on an external surface of the wick 42, whichprovides for a convenient arrangement for efficiently vaporisingaerosolizable material form the wick 42, in accordance with otherembodiments the vaporizer 40 may be configured to adopt other shapesand/or positions with respect to the wick 42 in the aerosol provisionsystem 1.

Turning to each sensor 200, in terms of how each sensor 200 may beconfigured to output a sensor signal to the control circuitry 18, itwill be appreciated that each such signal may be sent using either awired or wireless connection between the control circuitry 18 and therespective sensor 200. In the particular non-limiting embodiments shownin FIGS. 7-12 , a wired connection is provided between each sensor 200and the control circuitry 18, and which extends across the interface end54 and corresponding receptacle 8 between the control unit 4 and thecartridge 2 via the contact electrodes 46.

Similarly, in terms of how each sensor 200 may be powered, it will beappreciated that this may be achieved using either the power supply 16(as shown in the embodiments of FIGS. 7-10 ), or each sensor 200comprising its own power source (not shown in the Figures).

Finally, in respect of the exact type of each sensor 200, it will beappreciated that the type of sensor 200 will depend on the parameterwhich it is configured to measure. In that respect therefore, inaccordance with some embodiments, each sensor 200 may be configured tobe in contact with the wick 42 for detecting the at least one parameterof the wick 42. Alternatively, depending on the type of sensor 200 used,each sensor 200 may be configured to not be in contact with the wick 42for detecting the at least one parameter of the wick 42. Putdifferently, in such embodiments, each sensor 200 may comprise anon-contact sensor. Such a non-contact sensor 200, purely asnon-limiting example, in accordance with some embodiments might comprisea laser measure sensor (e.g. for detecting a physical dimensionparameter of the wick 42), and/or comprise a light emitter and a lightreceiver (e.g. for detecting an optical parameter of the wick 42, suchas its color and/or reflectivity).

Returning to the disclosure of FIGS. 10 and 11A-11C, another aspect ofthe present disclosure relates to the aerosol provision system 1 hereindescribed but which further comprises at least one doping agent which isconfigured to color the aerosolizable material transport element/wick 42a first color at a first predetermined condition, and which isconfigured to color the aerosolizable material transport element 42 asecond color, which is different from the first color, at a secondpredetermined condition which is different from the first predeterminedcondition.

In essence, and with reference to the operations described withreference to FIGS. 10 and 11A-11C, the above doping agent is configuredto make it more easy to identify, either visually, or for the opticalsensor to identify, any change in the color of the wick in instanceswhen a dry-out status of the aerosolizable material transport element 42is starting to occur. In this way, the presence of the doping agent maybe configured to speed up the response time, and improve the accuracy,of the aerosol provision system 1 to detect a dry-out status of thewick.

In the above respect therefore, at a broad level, there may be hereinprovided an aerosol provision system 1 comprising an aerosolizablematerial transport element (wick) 42 for receiving aerosolizablematerial, and a vaporizer 42 configured to vaporise the aerosolizablematerial received in the aerosolizable material transport element 42.The aerosol provision system 1 may further comprise at least one dopingagent which is configured to color the aerosolizable material transportelement 42 a first color at a first predetermined condition, and whichis configured to color the aerosolizable material transport element asecond color, which is different from the first color, at a secondpredetermined condition which is different from the first predeterminedcondition.

In terms of what the first and second predetermined condition might be,in accordance with some embodiments, the first predetermined conditionmay comprises a condition when a dry-out status of the aerosolizablematerial transport element has not occurred, and wherein the secondpredetermined condition comprises a condition when a dry-out status ofthe aerosolizable material transport element has occurred. In suchembodiments therefore, as explained previously, the doping agent may beconfigured to speed up the response time, and improve the accuracy, ofthe aerosol provision system 1 to detect a dry-out status of theaerosolizable material transport element.

In accordance with a more specific embodiment, the first predeterminedcondition may comprise a first moisture content of the aerosolizablematerial transport element, and the second predetermined condition maycomprise a second moisture content of the aerosolizable materialtransport element which is less than the first moisture content. In thisway therefore, in such embodiments the first moisture content maycorrespond to a moisture content for an aerosolizable material transportelement which is saturated with aerosolizable material. Whereas thesecond moisture content may correspond to a moisture content for theaerosolizable material transport element which is not saturated withaerosolizable material, and/or which is subject to a dry-out status.

In respect of the above embodiments, it is envisaged that the dopingagent might comprise a hydrochromic material, i.e. a material which isconfigured to change color when sufficiently exposed to moisture. Inthis way, when the hydrochromic material is sufficiently exposed to theaerosolizable material, the hydrochromic material may contribute to theformation of the first color, whereas when the hydrochromic material isinsufficiently exposed to the aerosolizable material (e.g. in a dry-outstatus), the hydrochromic material may contribute to the formation ofthe second color. Conveniently therefore, the implementation of thehydrochromic material may significantly increase the effectiveness ofthe aerosol provision system 1, and/or any corresponding optical sensor206, in so far as it may create a much greater contrast in color betweenconditions when the aerosolizable material transport element 42 issaturated with aerosolizable material and conditions when theaerosolizable material transport element 42 is in a dry-out status withinsufficient aerosolizable material in it. Put differently, andexplained illustratively, the surprising introduction of thehydrochromic material has been found to increase the contrast in colorexperienced between the color of the aerosolizable material transportelement shown in FIG. 11A and the color of the aerosolizable materialtransport element 42 shown in FIGS. 11B/11C.

With respect to the placement of the hydrochromic material in the aboveembodiments, in accordance with particular embodiments thereof, theaerosolizable material transport element may comprise the doping agentand/or the hydrochromic material.

In terms of the exact positioning of the hydrochromic material in theaerosolizable material transport element, in accordance with someparticular embodiments, the hydrochromic material may be provided as acoating on at least a portion of the aerosolizable material transportelement, and/or the hydrochromic material may be deposited or located onan external surface of the aerosolizable material transport element 42,such as the portion 208.

Alongside, or in addition to, any potential use of a hydrochromicmaterial in the doping agent, it is envisaged that the doping agentmight comprise a thermochromic material, i.e. a material which isconfigured to change color dependent on its temperature. In this way,when the thermochromic material is sufficiently cool (i.e. when theaerosolizable material transport element 42 is saturated withaerosolizable material), the thermochromic material may contribute tothe formation of the first color, whereas when the thermochromicmaterial is sufficiently hot (e.g. in a dry-out status, as a result ofthe elevated temperature in the aerosolizable material transport element42), the thermochromic material may contribute to the formation of thesecond color. Put differently therefore, in embodiments where athermochromic material is provided in the doping agent, in accordancewith such embodiments at least, the first predetermined condition maycomprise a first predetermined temperature of the aerosolizable materialtransport element, and the second predetermined condition may comprise asecond predetermined temperature which is higher than the firstpredetermined temperature of the aerosolizable material transportelement.

Conveniently, the implementation of the thermochromic material maysignificantly increase the effectiveness of the aerosol provision system1, and/or any corresponding optical sensor 206, in so far as it maycreate a much greater contrast in color between conditions when theaerosolizable material transport element 42 is saturated withaerosolizable material and conditions when the aerosolizable materialtransport element 42 is in a dry-out status with an elevatedtemperature. Put differently, and explained illustratively, the presenceof the thermochromic material may assist in the creation of an increasedcontrast in color experienced between the color of the aerosolizablematerial transport element shown in FIG. 11A and the color of the wickshown in FIGS. 11B/11C where the aerosolizable material transportelement is at an elevated temperature.

With respect to the placement of the thermochromic material in the aboveembodiments, in accordance with particular embodiments thereof, theaerosolizable material transport element may comprise the doping agentand/or the thermochromic material.

Where the thermochromic material is implemented in the aerosolizablematerial transport element, in accordance with some particularembodiments, the thermochromic material may be provided as a coating onat least a portion of the aerosolizable material transport element,and/or the thermochromic material may be deposited or located on anexternal surface of the aerosolizable material transport element 42,such as the portion 208.

Alternatively, it may be that the aerosolizable material comprises thedoping agent and/or the thermochromic material. In accordance with suchembodiments, upon the delivery of the thermochromic material to theaerosolizable material transport element 42 as part of the aerosolizablematerial, depending on the temperature of the aerosolizable materialtransport element 42, the color of the thermochromic material may changebetween the first color and the second color. Specifically, in instanceswhere the aerosolizable material transport element 42 is starting to dryout, and thus increases to an elevated temperature, at the point wherethe aerosolizable material is introduced to the aerosolizable materialtransport element 42 (AM_(in)), this elevation in temperature may causethe thermochromic material from the aerosolizable material at this pointto adopt the second color. Conversely, in a non dry-out status, thereduced temperature of the aerosolizable material transport element 42may cause the thermochromic material which is introduced to theaerosolizable material transport element 42 at the point AM_(in) toadopt/retain the first color.

Where the doping agent comprises a thermochromic material, in accordancewith some embodiments, the thermochromic material may also provide moreof a striking color to the aerosolizable material, which can make itmore easily identifiable by the optical sensor 206 in the embodimentswhere the optical sensor 206 is positioned as shown in FIGS. 10 and11A-11C, i.e. in the position which measures a portion 208 which is mostdistal from the locations where the aerosolizable material is configuredto be received in the wick 42 (AM_(in)). In that respect specifically,the presence of the thermochromic material in such embodiments may againconveniently increase the effectiveness of the aerosol provision system1, and/or any corresponding optical sensor 206, in so far as it maycreate a much greater contrast in color between conditions when theaerosolizable material transport element 42 is saturated withaerosolizable material and the colored thermochromic material (as perFIG. 11A) and conditions when the aerosolizable material transportelement 42 is in a dry-out status (as in FIGS. 11B and 11C) withinsufficient aerosolizable material in it.

In accordance with the foregoing therefore, the introduction of thethermochromic material in the doping agent may conveniently increase thecontrast in color experienced between the color of the aerosolizablematerial transport element shown in FIG. 11A and the color of theaerosolizable material transport element 42 shown in FIGS. 11B/11C. Andwhere the aerosolizable material comprises the thermochromic material,this may effectively also allow for an aerosolizable material for use inan aerosol provision system 1, wherein the aerosolizable materialcomprises at least one doping agent comprising a thermochromic material,wherein the thermochromic material is configured to adopt a first colorat a first predetermined temperature, and is configured to adopt asecond color at a second predetermined temperature, wherein the secondpredetermined temperature is higher than the first predeterminedtemperature.

In so far as any doping agent is provided, such as the above describedthermochromic material and/or hydrochromic material, where any resultantvapor from the aerosol provision system 1 is configured to be inhaled bythe user, in accordance with such embodiments the doping agent may benon-toxic. Also in so far as any doping agent is provided, such as theabove described thermochromic material and/or hydrochromic material, itwill be appreciated that the doping agent may be organic or inorganic,and may comprise any combination of a dye; paint; ink; or pigment,depending on how and where the doping agent is provided in the aerosolprovision system 1 (such as in the aerosolizable material transportelement 42 or in the aerosolizable material itself), as explainedpreviously.

For the sake of completeness, in accordance with these embodiments wherethe doping agent is provided, the aerosol provision system 1 inaccordance with some particular embodiments therefor may nonethelessinclude the control circuitry 18 and the at least one sensor 200;206 fordetecting the color of the aerosolizable material transport element 42.In such embodiments, as mentioned previously, each sensor 200;206 may bethen configured to output a sensor signal containing data related to thecolor of the aerosolizable material transport element; wherein thecontrol circuitry 18 is configured to process the data from the sensorsignal of each sensor 200;206 to determine the color of theaerosolizable material transport element.

In response to the control circuitry 18 in such embodiments determiningthe color of the aerosolizable material transport element as being thesecond color, the control circuitry 18 in some particular embodimentsthereof may be then configured to output the control signal, asexplained previously with respect to FIGS. 7-9 at least, and which mightfor instance comprise a command to disable the operation of the aerosolprovision system 1 and/or a command to disable the operation of thevaporizer 40; and/or which might comprise a command to provide anotification to a user.

In accordance with some embodiments provided herein, to potentiallyavoid the need for the control circuitry 18, a portion of theaerosolizable material transport element may be made visible to the userfor detecting the color of the aerosolizable material transport element.This might be achieved, for instance, by providing at least one window212 or at least one transparent/translucent portion 212 in the aerosolprovision system 1 through which the user may be configured to manuallyobserve the color of the aerosolizable material transport element 42,from a position outside the aerosol provision system 1. Such anembodiment is shown in FIG. 12 .

Thus, described herein are a number of configurations for the aerosolprovision system 1 which conveniently allow it to measure at least oneparameter of the aerosolizable material transport element (wick) 42 todetermine a status of thereof, such as a dry-out status thereof.

Moving away from FIG. 7-12 , and turning now to the embodiments of FIG.13 (and also FIG. 14 ), there is shown schematically a cross sectionview of another modified version of the aerosol provision system 1,including the cartridge 2 and the control unit 4. The aerosol provisionsystem 1; cartridge 2; and control unit 4 shown in FIGS. 13 and 14 arebased on the construction of the corresponding aerosol provision system1; cartridge 2; and control unit 4; shown in FIGS. 1-6B, and comprisesimilar components as set out by the reference numerals that are commonto both sets of Figures. For instance, the cartridge 2 from FIGS. 13 and14 comprise a vaporizer 40, which comprises a heating element, andwherein the cartridge 2 defines a reservoir 31 which extends around anaerosol outlet tube 38. In accordance with such embodiments, thereservoir 31 may be annular, and is configured for containingaerosolizable material for aerosolising. Similarly, the control unit 4from FIGS. 13-14 may comprise the plastic outer housing 10 including thereceptacle wall 12 that defines the receptacle 8 for receiving the endof the cartridge 2. The control unit 4 from FIG. 13-14 may also comprisethe control circuitry 18 and the power supply/battery 16. In suchembodiments, the cartridge 2 may comprise the contact electrodes 46 forengaging with the control unit 4 for transferring power between thecontrol circuitry 18 in the control unit 4 and the vaporizer 40 in thecartridge 2.

Conscious of the above, and starting with FIG. 13 , a first modificationto the aerosol provision system is it being configured to monitor atleast one parameter of the vaporizer 40, which is not the electricalresistance of the heating element, to determine a failure state of theaerosol provision system 1. At its broadest level, it is envisaged thatsuch a failure state could correspond to any adverse state in theaerosol provision system. Though in accordance with some particularembodiments, the failure state could correspond to the vaporizerexceeding a predetermined temperature, and/or the vaporizer experiencinga dry-out state. In such a dry-out state, this may correspond to a statewhere the vaporizer 40 is not saturated with aerosolizable material.During such a dry-out state therefore, as the vaporizer 40 is operated,this may cause the vaporizer 40 to become excessively hot, as a resultof there being an insufficient amount of aerosolizable material in theproximity of the vaporizer 40 to help cool the vaporizer 40 down.

In such a dry-out state, in so far as the aerosol provision system 1 isconfigured to monitor at least one parameter of the vaporizer 40 todetermine a failure state of the aerosol provision system 1 (which insome particular embodiments could correspond to a failure state of thevaporizer 40), this may allow the aerosol provision system 1 to react insuch instances where a dry-out state is detected, as will be described.

From the foregoing therefore, there may be effectively provided anaerosol provision system comprising 1 a reservoir 31 for aerosolizablematerial; and a vaporizer 40, comprising a heating element, forvaporising aerosolizable material from the reservoir, wherein theaerosol provision system 1 is configured to monitor at least oneparameter of the vaporizer 40, which is not the electrical resistance ofthe heating element, to determine a failure state of the aerosolprovision system 1.

In accordance with some embodiments, the aerosol provision system 1 mayfurther comprise the control circuitry 18, such that the controlcircuitry 18 is configured to determine the failure state of the aerosolprovision system 1. In accordance with such embodiments, the aerosolprovision system may be further provided with at least one sensor 300for monitoring the at least one parameter, wherein each sensor 300 isconfigured to output a sensor signal containing data related to the atleast one parameter to the control circuitry 18. With such data, thecontrol circuitry 18 may be configured to process the data from thesensor signal of each sensor 300 to determine the failure state of theaerosol provision system 1.

In terms of what the above described at least one parameter may be, itis envisaged that this at least one parameter could comprise a number ofdifferent parameters relating to the vaporizer 40 as will be described.

In the above respect, and with reference to FIG. 13 , in accordance withsome embodiments, the at least one parameter may comprise a magneticparameter of the vaporizer 40. In accordance with some particularembodiments thereof, the at least one sensor 300 may then comprise afirst sensor 302 for detecting the magnetic parameter, and foroutputting a first sensor signal containing first data related to themagnetic parameter. In terms of what such a first sensor 302 might be,it is envisioned that this sensor may be any sensor which is able tomonitor the magnetic parameter. In that respect, and in a veryparticular embodiment, the first sensor may comprise a Hall effectsensor.

In accordance with a particular embodiment where the parameter is amagnetic parameter, the magnetic parameter may comprise the magneticfield strength generated by the vaporizer 40. In accordance with suchembodiments, the control circuitry 18 may be then configured todetermine a magnetic field strength value from the first data of thefirst sensor signal; compare the magnetic field strength value against apredetermined magnetic field strength value; and then determine thefailure state of the aerosol provision system 1 in the event that themagnetic field strength value is less than the predetermined magneticfield strength value. In the above respect, and particularly where thefailure state corresponds to a dry-out state of the vaporizer 40, as thetemperature of the vaporizer 40 increases, the magnetic field strengthfrom the vaporizer 40 may be begin to decrease. Accordingly, by settingthe predetermined magnetic field strength value to a temperature of thevaporizer 40 which corresponds to the failure/dry-out state of thevaporizer 40, the above embodiments may provide for a convenientarrangement for detecting the failure state of the aerosol provisionsystem 1.

In accordance with some embodiments where the at least one parametercomprises a magnetic parameter, to further facilitate the aerosolprovision system 1 being able to determine the failure state, thevaporizer 40 may comprise a ferromagnetic material, which in accordancewith some particular embodiments may comprise a Curie temperature whichis greater than a first predetermined temperature, and which is lessthan a second predetermined temperature, wherein the secondpredetermined temperature is higher than the first predeterminedtemperature. In accordance with such particular embodiments, the firstpredetermined temperature may correspond to an operating temperature ofthe vaporizer where the vaporizer is saturated with aerosolizablematerial. Conversely, the higher second predetermined temperature maycorrespond to a temperature of the vaporizer 40 when the vaporizer 40 isno longer saturated with aerosolizable material, i.e. when the vaporizeris subject to a dry-out state.

Where such a Curie temperature is employed, in accordance with someembodiments thereof, the predetermined magnetic field strength value maycorrespond to the magnetic field strength of the vaporizer 40 at theCurie temperature, i.e. at a temperature when the failure state of theaerosol provision system 1 is indicative. As to the exact material forthe vaporizer 40 which may provide such a required Curie temperature, itwill be appreciated that this material may be selected depending on theparticular relative geometry and materials used in the aerosol provisionsystem 1. In accordance with some very particular non-limitingembodiments, however, it has been found that a ferromagnetic materialcomprising an alloy comprising nickel and chromium may provide aparticularly suitable Curie temperature in accordance with the aerosolprovision systems 1 comprising the geometry and features describedherein, and as shown in the Figures.

Aside from the monitoring of any magnetic parameter, yet staying withFIG. 13 , in accordance with some embodiments, the at least oneparameter may alternatively/additionally comprise an emissivityparameter of the vaporizer 40. In accordance with such embodiments, theat least one sensor 300 may then comprise a second sensor 304 (as shownin FIG. 13 ), such as (but not limited to) an infrared sensor, fordetecting the emissivity parameter, and for outputting a second sensorsignal containing second data related to the emissivity parameter. Withrespect to such an emissivity parameter, as the temperature of vaporizer40 changes (e.g. between a first operating temperature of the vaporizerwhere the vaporizer is saturated with aerosolizable material, and ahigher second temperature when the vaporizer is no longer saturated withaerosolizable material), the emissivity of the vaporizer will change inaccordance with this temperature change. From the foregoing therefore,and in accordance with some embodiments, the second data may be relatedto the emissivity parameter from any relevant portion of the vaporizer40, such as an external surface thereof.

With any such second data, the control circuitry 18 may be configured todetermine an emissivity value from the second data of the second sensorsignal, and then compare the emissivity value against at least onepredetermined emissivity value to determine the failure state of theaerosol provision system 1. Such an emissivity value in accordance withsome particular embodiments may vary between 0 and 1. In terms of thepredetermined emissivity value, this will appreciably depend on thecomposition of the vaporizer 40, and its notional emissivity at thepoint where the failure/dry-out state occurs. In that respect therefore,where the control circuitry 18 determines that the emissivity valuesufficiently deviates from the predetermined emissivity value, i.e. isgreater than and/or less than the predetermined emissivity value by apredetermined amount, the control circuitry 18 may be then configured todetermine the failure state of the aerosol provision system 1.

In accordance with some embodiments, the at least one parameter maycomprise a resonant frequency of the vaporizer 40, such that the controlcircuitry 18 may be further configured to determine the resonantfrequency of the vaporizer; and compare the resonant frequency againstat least one predetermined frequency value to determine the failurestate of the aerosol provision system.

In accordance with such embodiments, it will be appreciated that as thetemperature of the vaporizer 40 changes, the corresponding resonantfrequency of the vaporizer will also change. Any such changes in theresonant frequency will be particularly noticeable where the vaporizercomprises a heating element such as a heating coil, such as in thearrangement shown in FIGS. 13 and 14 . More specifically in the aboverespects, as the temperature of the vaporizer 40 changes, any perceivedreactance (capacitive and/or inductance) properties of the vaporizer 40will change based on the temperature of the vaporizer 40. Commensuratelytherefore, any temperature of the vaporizer 40 will cause the vaporizerto exhibit a particular resonant frequency for that temperature, whichcan be determined by the control circuitry 18, and then compared withthe predetermined frequency value.

With respect to how the resonant frequency may be determined by thecontrol circuitry 18, it will be appreciated that this may be achievedin a number of different ways. In accordance with a particular(non-limiting) embodiment, the resonant frequency could be determined bythe control circuitry 18 applying a predetermined voltage to thevaporizer 40, at a plurality of different frequencies. The controlcircuitry 18 may then compare the voltage response across the vaporizer40 for each frequency to determine the resonant frequency. In accordancewith some particular embodiments thereof, the predetermined voltage maybe provided by the power supply 16.

Similarly, in respect of the predetermined frequency value, it isenvisaged that the predetermined frequency value may correspond to theresonant frequency of the vaporizer at the cusp of a failure (dry-out)state, whereat the vaporizer is no longer saturated with aerosolizablematerial.

In accordance with the above embodiments, and other embodiment alike,the aerosol provision system 1 may comprise a power supply 16 configuredto provide alternating current, AC, power to the vaporizer 40, forfacilitating the determination of the resonant frequency.

Staying with a frequency response of the vaporizer 40, and turning toFIG. 14 , in accordance with some embodiments, the at least oneparameter may comprise a frequency of vibration of the vaporizer,wherein the aerosol provision system 1 further comprises a third sensor306 for detecting the frequency of vibration of the vaporizer 40. Inaccordance with such embodiments, during the operation of the vaporizer40, a vibrational effect may be created therein as a result of the powerprovided by the power supply 16 to the vaporizer 40.

Such a vibrational effect may therefore result in a vibration frequencycreating an audible and/or visible response, which can be detected bythe third sensor 306. Although not limited thereto, such vibrations maybe particularly prevalent for a vaporizer 40 taking the form of aheating coil 40, shown in the FIG. 14 , where the reactance propertiesof the coil shape may create more prevalent vibrations.

As to the type of third sensor 306 employed in the above embodiments, inaccordance with some particular embodiments thereof, the third sensor306 may comprise a vibration sensor; a microphone; and/or apiezoelectric sensor for detecting the vibration frequency of thevaporizer 40. Any such third sensor 306, as required, may also be acontact sensor which is in contact with the vaporizer 40 (as shown inFIG. 14 ), or a non-contact sensor (e.g. in the case of the third sensorbeing a microphone).

Whatever the type of third sensor 306 which is employed, in accordancewith some embodiments, the third sensor 306 may be configured to outputa third sensor signal, to the control circuitry 18, containing datarelated to the frequency of vibration of the vaporizer 40. In suchembodiments, the control circuitry 18 may be then configured to processthe data from the third sensor signal to determine the vibrationfrequency of the vaporizer 40, and then compare the vibration frequencyagainst at least one predetermined vibration frequency value todetermine the failure state of the aerosol provision system.

In the above respect, and concerning the predetermined vibrationfrequency value, it is envisaged that this may correspond to theexhibited vibration frequency of the vaporizer at the cusp of a failure(dry-out) state, whereby the vaporizer 40 is no longer saturated withaerosolizable material.

From the foregoing therefore, it will be seen that a variety ofdifferent parameters of the vaporizer 40 have been described, and whichcan be monitored by the aerosol provision system 1 to determine afailure state of the aerosol provision system 1, such as a dry-outstate.

Whatever the parameter(s) of the vaporizer 40 which is monitored, inresponse to detecting the failure state, the control circuitry 18 inaccordance with some embodiments may be configured to control anoperation of the aerosol provision system, such as disabling theoperation of the aerosol provision system 1 and/or disabling theoperation of the vaporizer 40. In accordance with some embodiments, thecontrol circuitry 18 may be further configured to generate an outputsignal for providing a notification to a user. In accordance with someembodiments thereof, the output signal may comprise at least one of: anoptical signal, an acoustic signal, and a haptic signal, which can beused to provide a notification to the user.

Such a notification, in accordance with some particular embodiments, mayinclude any of: a notification to the user that the aerosolizablematerial requires refilling; that the cartridge 2 requires replacing(where a cartridge 2/control unit 4 arrangement is employed); and/or anotification to the user that at least a portion of the aerosolprovision system 1 has overheated.

To implement the above notifications, as required, in accordance withsome embodiments, the aerosol provision system 1 may further compriseany one or combination of an optic element (such as an LED), an acousticelement (such as a speaker) and a haptic feedback element (such as avibrator). Appreciably, in some particular embodiments to those set outabove, any such optical/acoustic/haptic feedback element(s) may be mostconveniently located on the control unit 4 (where such a cartridge2/control unit 4 arrangement is employed).

With regards to the mechanisms described herein for determining thefailure state of the aerosol provision system 1, it will be appreciatedthese mechanisms may be applicable to any aerosol provision system 1whereby the vaporizer 40 is configured for vaporising aerosolizablematerial from a reservoir 31 of such aerosolizable material. In thatrespect, any delivery mechanism may be provided for transferring theaerosolizable material from the reservoir 31 to the vaporizer 40. Inaccordance with some embodiments, this delivery mechanism may comprisethe wick 42. In such embodiments, the wick 42 may be configured toreceive the aerosolizable material from the reservoir 31, wherein thevaporizer 40 is configured to vaporise the aerosolizable materialreceived in the wick 42.

Where the wick 42 is present, it will be appreciated that the wick 42may take several forms. In accordance with some embodiments, such as theaerosol provision systems 1 shown in the Figures, the wick 42 may be acapillary wick comprising a first end 42A and a second end 42B which isopposite the first end 42A. Equally, the wick 42 may comprise a fibrousmaterial, and/or in some embodiments may comprise a ceramic material.

Where the wick 42 comprises a ceramic material, in some particularembodiments thereof, the vaporizer 40 may comprise a conductive materiallocated on an external surface of the wick 42. Such conductive materialmay appreciably take any required shape on the surface of the wick 42,e.g. a spiral pattern; a raster pattern; or a zig-zag pattern such toallow the vaporizer 40 to efficiently vaporise the aerosolizablematerial in the wick 42. As will be appreciated, the conductive materialmay be connected to the connection leads 41 which deliver power to thevaporizer 40.

With regard to the construction of the vaporizer 40 which might be usedwith the aerosol provision systems 1 described herein, it will beappreciated that the vaporizer 40 may take a variety of different forms.In that respect, and in accordance with some particular embodiments, thevaporizer 40 may comprise a heating element such as a heating coil. Inaccordance with some particular embodiments where the wick 42 ispresent, in such embodiments the heating coil may be coiled, and/orextend around, the wick 42 (e.g. as shown in the Figures). Equally, asnoted above, in accordance with some other embodiments, the vaporizer 40might be located on a wick 42 comprising a ceramic material.

Appreciating the foregoing, it is envisaged that the mechanismsdescribed herein for determining the failure state of the aerosolprovision system 1 may be located in a number of different aerosolprovision system 1, and in a number of different configurations withrespect to the remaining components of each such aerosol provisionsystem 1. In accordance with some embodiments, such as that shown inFIGS. 13 and 14 , the mechanism may be located in an aerosol provisionsystem 1 comprising the cartridge and the control unit 4. In suchembodiments, the reservoir 31 and the vaporizer 40, along with anyprovided sensor(s) 300 may be located in the cartridge 2. In suchembodiments, the control unit 4 may then comprise the cartridgereceiving section 8 that includes the interface arranged tocooperatively engage with the cartridge 2 so as to releasably couple thecartridge 2 to the control unit 4.

Equally, in some embodiments, the entirety of the detecting mechanismmay be located in the cartridge 2. In such embodiments, there may beprovided, at least, a cartridge 2 for an aerosol provision system 1comprising the cartridge 2 and a control unit 4, wherein the cartridge 2comprises: the reservoir 31 for aerosolizable material; and thevaporizer 40, comprising the heating element, for vaporisingaerosolizable material from the reservoir 31. In accordance with suchembodiments, the cartridge 2 may be configured to monitor at least oneparameter of the vaporizer 40, which is not the electrical resistance ofthe heating element 40, to determine a failure state of the cartridge 2,such as (but not limited to) a dry-out state of the cartridge 2.

In embodiments where the control unit 4 comprises a portion of thedetecting mechanism, such as the control circuitry 18 and the powersupply 16, there may be provided a corresponding mechanism fortransferring power and/or any signals between the portion of thedetecting mechanism in the control unit 4, and the remaining portion(such as the vaporizer 40 and any sensor(s) 300) present in thecartridge 2. In that respect therefore, and in accordance with someembodiments such as those shown in FIGS. 13 and 14 , a wired connectionmay be provided between the cartridge 2 and the control unit 4, andwhich extends across the interface end 54 and corresponding receptacle 8between the control unit 4 and the cartridge 2 via the contactelectrodes 46, for transferring power/signals between the cartridge andthe control unit 4. It will be appreciated that in such embodimentshowever, a wireless connection could equally be used to bridge anyrequired power/signals between the cartridge 2 and the control unit 4,such to obviate the need for the contact electrodes 46.

In accordance with certain embodiments of the disclosure, a cartridgefor an aerosol provision system may generally comprise a housing parthaving a mouthpiece end and an interface end, wherein the mouthpiece endincludes an aerosol outlet for the cartridge and the interface endincludes an interface for coupling the cartridge to a control unit. Anair channel wall (which may be formed by various components of thecartridge) extends from an air inlet for the cartridge to the aerosoloutlet via an aerosol generation region in the vicinity of a vaporizer.The cartridge has a reservoir within the housing part containingaerosolizable material for aerosolization. The reservoir is defined by aregion within the housing part which is outside the air channel and anend of the reservoir at the interface end of the housing part is sealedby a resilient plug comprising a base part and an outer wall, whereinthe outer wall of the resilient plug forms a seal with an inner surfaceof the housing part. Respective ends of a aerosolizable materialtransport element pass through opening in the air channel or into thereservoir so as to convey aerosolizable material from the reservoir tothe vaporizer.

One aspect of some particular cartridge configurations in accordancewith certain embodiments of the disclosure is the manner in which theresilient plug 44 provides a seal to the housing part 32. In particular,in accordance with some example implementations the outer wall 102 ofthe resilient plug 44 which seals to the inner surface of the housingpart 32 to form the end of the aerosolizable material reservoir extendsin direction parallel to the longitudinal axis of the cartridge to aposition which is further from the interface end of the cartridge thanthe aerosolizable material transport element/vaporizer. That is to say,the ends of the aerosolizable material transport element extends intothe aerosolizable material reservoir in a region which is surrounded bythe outer sealing wall of the resilient plug. Not only does this helpseal the reservoir against leakage, it allows the geometry of thereservoir in the region which supplies the aerosolizable materialtransport element with aerosolizable material to be governed by thegeometry of the resilient plug. For example, the radial thickness of thereservoir in this region can readily be made smaller than the radialthickness in other longitudinal positions along the air channel, whichcan help trap aerosolizable material in the vicinity of theaerosolizable material transport element, thereby helping to reduce therisk of dry out for different orientations of the cartridge during use.

The outer wall of the resilient plug may, for example, contact the innersurface of the housing part at locations over a distance of at least 5mm, 6 mm, 7 mm, 8 mm, 9 mm and 10 mm in a direction extending from theinterface end to the mouthpiece end (i.e. parallel to the longitudinalaxis). The outer wall of the resilient plug may be in contact with theinner surface of the housing over the majority of this distance, or theouter wall of the resilient plug may include a number of (e.g. four)circumferential ridges 140 to help improve sealing. The resilient plugmay be slightly oversized relative to the opening in the housing part sothat it is biased into slight compression. For example, for theimplementation shown in FIG. 3B, the interior width of the housing partinto which the resilient plug is inserted in the plane of this figure isaround 17.5 mm, whereas the corresponding width of the resilient plug isaround 18 mm, thereby placing the resilient plug into compression wheninserted into the housing part. As can be most readily seen in FIGS. 5Ato 5C, whereas the outer cross section of the cartridge housing part issymmetric under a 180° rotation, the resilient plug 44 does not have thesame symmetry because it includes a flat 142 on one side to accommodatethe air channel gap 76 provided by the double-walled section 74 of thehousing part (i.e. the resilient plug is asymmetric in a planeperpendicular to a longitudinal axis of the cartridge to accommodate thedouble-walled section of the housing part).

In terms of the radial size/width of the reservoir in the annular regionwhere the aerosolizable material transport element extends into thereservoir, a distance between the air channel wall and the outer wall ofthe resilient plug in this region may, for example, be in the range 3 mmto 8 mm. In the example cartridge discussed above which has a generallyoval housing part and a generally circular air channel, it will beappreciated the thickness of the reservoir is different at differentlocations around the air channel. In this example the aerosolizablematerial transport element is arranged to extend into the reservoir inthe region where it is widest in the axial direction, i.e. into the“lobes” of the oval reservoir around the air channel. The portions ofthe aerosolizable material transport element that extend into thereservoir may, for example, have a length, as measured from the interiorof the air channel wall, in the range 2 mm to 8 mm, e.g. in the range 3mm to 7 mm or in the range 4 mm to 6 mm. The specific geometry in thisregard (and for other aspects of the configuration) may be chosen havingregard to a desired rate of aerosolizable material transport, forexample having regard to the capillary strength of the aerosolizablematerial transport element and the viscosity of the aerosolizablematerial, and may be established for a given cartridge design throughmodelling or empirical testing.

Another aspect of some particular cartridge configurations in accordancewith certain embodiments of the disclosure is the manner in which theair channel is routed through the cartridge, and in particular from theair inlet to the vicinity of the vaporizer (the aerosol generationregion). In particular, whereas in a conventional cartridges an airinlet is typically provided at the interface end of the cartridge, inaccordance with certain embodiments of the disclosure, an air inlet forthe cartridge is located in a side wall of the housing part at aposition which is further from the interface end than at least a part ofthe resilient plug that seals an end of the reservoir. Thus, the airchannel in the cartridge is initially routed from the air inlet towardsthe interface end and bypasses the resilient plug before changingdirection and entering the aerosol generation chamber through theresilient plug. This can allow the outer surface of the cartridge at theinterface end, where it is closest to the vaporizer, to be closed,thereby helping to reduce the risk of leakage from the cartridge, bothin terms of aerosolizable material coming through the openings in theair channel which is not retained by the aerosolizable materialtransport element in the air channel (e.g. due to saturation/agitation)or aerosolizable material that has being vaporised but condensed back toaerosolizable material in the air channel during use. In someimplementations, a distance from air inlet to the interface end of thehousing part may be at least 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm.

In some example implementations an absorbent element, for example aportion of sponge material or a series of channels forming a capillarytrap, may be provided between the air inlet and the aerosol generationchamber, for example in the region air channel formed between the baseof the resilient plug and the end cap, to further help reduce the riskof leakage by absorbing aerosolizable material that forms in the airchannel and so helping prevent the aerosolizable material travellingaround the air channel through the air inlet or towards the aerosoloutlet.

In some example implementations the air channel from the air inlet tothe aerosol outlet may have its smallest cross-sectional area where itpasses through the hole 106 in the resilient plug. That is to say, thehole in the resilient plug may be primarily responsible for governingthe overall resistance to draw for the electronic cigarette.

Another aspect of some particular cartridge configurations in accordancewith certain embodiments of the disclosure is the manner in which thedividing wall element divides the air reservoir into two regions, namelya main region above the dividing wall (i.e. towards a mouthpiece end ofthe cartridge) and a aerosolizable-material-supply region below thedividing wall (i.e. on the same side of the dividing wall as where theaerosolizable material transport element extends from the vaporizer intothe reservoir). The dividing wall includes openings to govern the flowof aerosolizable material on the main region to the aerosolizablematerial supply region. The dividing wall can help retain aerosolizablematerial in the aerosolizable material supply region of the reservoir,example when the electronic cigarette is tilted through variousorientations, which can help avoid dry out. The dividing wall can alsoconveniently provide a mechanical stop for the resilient plug toabut/press against so as to help correctly locate the resilient plugduring assembly and maintain the resilient plug in slight compressionbetween the dividing wall and the end cap when the cartridge isassembled.

In the example discussed above, the dividing wall is formed as aseparate element form the housing part, wherein an inner surface of thehousing part includes one or more protrusions arranged to contact theside of the dividing wall facing the mouthpiece end of the cartridge tolocate the dividing wall along a longitudinal axis of the cartridge, butin other examples the dividing wall may be integrally formed with thehousing part.

In the example discussed above the dividing wall is in the form of anannular band around the air channel and comprises four fluidcommunication openings 150 located in respective quadrants of the band.However, more or fewer openings through the dividing wall may beprovided in different implementations. Individual openings may, forexample, have an area of between 4 mm² and 15 mm².

A combined area for the at least one openings as a fraction of the totalarea of the dividing wall exposed to aerosolizable material supplyregion of the reservoir region may be, for example, from 20% to 80%; 30%to 70% or 40% to 60%.

It will be appreciated that while the above description has focused onsome specific cartridge configurations comprising a number of differentfeatures, cartridges in accordance with other embodiments of thedisclosure may not include all these features. For example, in someimplementations an air path generally of the kind discussed above, i.e.with an air inlet which is in a sidewall of the cartridge and closer tothe mouthpiece end of the cartridge than the vaporizer, may be providedin a cartridge which does not include a resilient plug with an outersealing wall which extends around the vaporizer and/or does not includea dividing wall element of the kind discussed above. Similarly, acartridge which does include a resilient plug with an outer sealing wallwhich extends around the vaporizer may have an air inlet into thecartridge which is at the interface end of the cartridge, and not in asidewall, and which may also not have a dividing wall element of thekind discussed above. Furthermore, a cartridge which does include adividing wall element, might not include an air inlet located furtherfrom the interface end of the cartridge than the vaporizer and/or anextended outer sealing wall for a resilient plug as discussed above.

Thus, there has been described an aerosol provision system comprising areservoir for aerosolizable material; a wick configured to receive theaerosolizable material from the reservoir, a vaporizer configured tovaporise the aerosolizable material received in the wick, wherein theaerosol provision system is configured to measure at least one parameterof the wick to determine a status of the wick.

There has also been described a cartridge for an aerosol provisionsystem comprising the cartridge and a control unit, wherein thecartridge comprises:

-   -   a reservoir for aerosolizable material;    -   a wick configured to receive the aerosolizable material from the        reservoir; and    -   a vaporizer configured to vaporise the aerosolizable material        received in the wick,    -   wherein the cartridge is configured to measure at least one        parameter of the wick to determine a status of the wick.

There has also been described an aerosolizable material for use in anaerosol provision system, wherein the aerosolizable material comprisesat least one doping agent comprising a thermochromic material, whereinthe thermochromic material is configured to adopt a first color at afirst predetermined temperature, and is configured to adopt a secondcolor at a second predetermined temperature, wherein the secondpredetermined temperature is higher than the first predeterminedtemperature.

There has also been described a cartridge for an aerosol provisionsystem comprising the cartridge and a control unit, wherein thecartridge comprises:

-   -   an aerosolizable material transport element for receiving        aerosolizable material, and a vaporizer configured to vaporise        the aerosolizable material received in the aerosolizable        material transport element, and    -   at least one doping agent which is configured to color the        aerosolizable material transport element a first color at a        first predetermined condition, and which is configured to color        the aerosolizable material transport element a second color,        which is different from the first color, at a second        predetermined condition which is different from the first        predetermined condition.

There has also been described an aerosol provision system comprising anaerosolizable material transport element for receiving aerosolizablematerial, and a vaporizer configured to vaporise the aerosolizablematerial received in the aerosolizable material transport element;

-   -   wherein the aerosol provision system further comprises at least        one doping agent which is configured to color the aerosolizable        material transport element a first color at a first        predetermined condition, and which is configured to color the        aerosolizable material transport element a second color, which        is different from the first color, at a second predetermined        condition which is different from the first predetermined        condition.

There has also been described an aerosolizable material transportelement for receiving aerosolizable material, wherein the aerosolizablematerial transport element comprises at least one doping agent which isconfigured to color the aerosolizable material transport element a firstcolor at a first predetermined condition, and which is configured tocolor the aerosolizable material transport element a second color, whichis different from the first color, at a second predetermined conditionwhich is different from the first predetermined condition.

There has also been described an aerosol provision system comprising:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the aerosol provision system is configured to monitor at        least one parameter of the vaporizer, which is not the        electrical resistance of the heating element, to determine a        failure state of the aerosol provision system.

There has also been described a cartridge for an aerosol provisionsystem comprising the cartridge and a control unit, wherein thecartridge comprises:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the cartridge is configured to monitor at least one        parameter of the vaporizer, which is not the electrical        resistance of the heating element, to determine a failure state        of the cartridge.

There has also been described an aerosol provision system 1 comprising areservoir 31 for aerosolizable material; a wick 42 configured to receivethe aerosolizable material from the reservoir 31, a vaporizer 40configured to vaporise the aerosolizable material received in the wick42, wherein the aerosol provision system 1 is configured to measure atleast one parameter of the wick 42 to determine a status of the wick 42.The parameter may be the moisture content of the wick 42, at least onephysical dimension of the wick 42, and/or an optical parameter, such asthe color of an external surface of the wick 42, or the reflectivity ofan external surface of the wick 42.

While the above described embodiments have in some respects focused onsome specific example aerosol provision systems, it will be appreciatedthe same principles can be applied for aerosol provision systems usingother technologies. That is to say, the specific manner in which variousaspects of the aerosol provision system function, for example in termsof the underlying form of the vaporizer or vaporizer technology used arenot directly relevant to the principles underlying the examplesdescribed herein.

In that respect, it will also be appreciated that various modificationsmay be made to the embodiments of aerosol provision system describedherein. For instance, although the vaporizer 40 has been described in anumber of the above embodiments as being located in the cartridge, itwill be appreciated that in some embodiments the vaporizer may belocated in the control unit of the aerosol provision system.

In order to address various issues and advance the art, this disclosureshows by way of illustration various embodiments in which the claimedinvention(s) may be practiced. The advantages and features of thedisclosure are of a representative sample of embodiments only, and arenot exhaustive and/or exclusive. They are presented only to assist inunderstanding and to teach the claimed invention(s). It is to beunderstood that advantages, embodiments, examples, functions, features,structures, and/or other aspects of the disclosure are not to beconsidered limitations on the disclosure as defined by the claims orlimitations on equivalents to the claims, and that other embodiments maybe utilised and modifications may be made without departing from thescope of the claims. Various embodiments may suitably comprise, consistof, or consist essentially of, various combinations of the disclosedelements, components, features, parts, steps, means, etc. other thanthose specifically described herein, and it will thus be appreciatedthat features of the dependent claims or clauses may be combined withfeatures of the independent claims or independent clauses incombinations other than those explicitly set out in the claims andclauses. The disclosure may include other inventions not presentlyclaimed, but which may be claimed in future. In effect, any combinationof feature(s) from one set of claims many be combined with any otherindividual feature(s) from any of the remaining set of claims orclauses.

First Set of Clauses

1. An aerosolizable material for use in an aerosol provision system,wherein the aerosolizable material comprises at least one doping agentcomprising a thermochromic material, wherein the thermochromic materialis configured to adopt a first color at a first predeterminedtemperature, and is configured to adopt a second color at a secondpredetermined temperature, wherein the second predetermined temperatureis higher than the first predetermined temperature.

2. An aerosolizable material according to clause 1, wherein theaerosolizable material is liquid.

3. An aerosolizable material according to any preceding clause, whereinthe aerosolizable material is a gel.

4. A cartridge for an aerosol provision system, wherein the cartridgecontains a reservoir containing the aerosolizable material according toany preceding clause, and an aerosol forming substrate for receiving theaerosolizable material from the reservoir.

5. An aerosol provision system according to any of clauses 1-3, whereinthe aerosol provision system contains a reservoir for containing theaerosolizable material according to clause 1, and an aerosol formingsubstrate for receiving the aerosolizable material from the reservoir.

6. A cartridge for an aerosol provision system comprising the cartridgeand a control unit, wherein the cartridge comprises:

-   -   an aerosolizable material transport element for receiving        aerosolizable material, and a vaporizer configured to vaporise        the aerosolizable material received in the aerosolizable        material transport element, and    -   at least one doping agent which is configured to color the        aerosolizable material transport element a first color at a        first predetermined condition, and which is configured to color        the aerosolizable material transport element a second color,        which is different from the first color, at a second        predetermined condition which is different from the first        predetermined condition.

7. A cartridge for an aerosol provision system according to clause 6,wherein the cartridge further comprises a reservoir for containingaerosolizable material, and wherein the aerosolizable material transportelement is configured to receive the aerosolizable material from thereservoir.

8. An aerosol provision system comprising an aerosolizable materialtransport element for receiving aerosolizable material, and a vaporizerconfigured to vaporise the aerosolizable material received in theaerosolizable material transport element,

-   -   wherein the aerosol provision system further comprises at least        one doping agent which is configured to color the aerosolizable        material transport element a first color at a first        predetermined condition, and which is configured to color the        aerosolizable material transport element a second color, which        is different from the first color, at a second predetermined        condition which is different from the first predetermined        condition.

9. An aerosol provision system according to clause 8, wherein theaerosol provision system further comprises a reservoir for containingaerosolizable material, and wherein the aerosolizable material transportelement is configured to receive the aerosolizable material from thereservoir.

10. An aerosol provision system according to clause 8 or 9, wherein theaerosolizable material transport element comprises the doping agent.

11. An aerosol provision system according to any of clauses 8 to 10,further comprising the aerosolizable material.

12. An aerosol provision system according to clause 11, wherein theaerosolizable material comprises the doping agent.

13. An aerosol provision system according to clause 11 or 12, whereinthe aerosolizable material comprises a liquid.

14. An aerosol provision system according to clause 11 or 12, whereinthe aerosolizable material comprises a gel.

15. An aerosol provision system according to any of clauses 8 to 14,wherein the doping agent comprises a hydrochromic material.

16. An aerosol provision system according to any of clauses 8 to 15,wherein the first predetermined condition comprises a first moisturecontent of the aerosolizable material transport element, and the secondpredetermined condition comprises a second moisture content of theaerosolizable material transport element which is less than the firstmoisture content.

17. An aerosol provision system according to any of clauses 8-16,wherein the doping agent comprises a thermochromic material.

18. An aerosol provision system according to any of clauses 8-17,wherein the first predetermined condition comprises a firstpredetermined temperature of the aerosolizable material transportelement, and the second predetermined condition comprises a secondpredetermined temperature which is higher than the first predeterminedtemperature of the aerosolizable material transport element.

19. An aerosol provision system according to any of clauses 8-18,wherein the doping agent comprises a dye or pigment.

20. An aerosol provision system according to any of clauses 8-19,wherein the aerosol provision system comprises control circuitry and atleast one sensor for detecting the color of the aerosolizable materialtransport element, wherein each sensor is configured to output a sensorsignal containing data related to the color of the aerosolizablematerial transport element; and

-   -   wherein the control circuitry is configured to process the data        from the sensor signal of each sensor to determine the color of        the aerosolizable material transport element.

21. An aerosol provision system according to clause 20, wherein responseto the control circuitry determining the color of the aerosolizablematerial transport element as being the second color, the controlcircuitry is configured to output a control signal.

22. An aerosol provision system according to any of clauses 8-21,wherein a portion of the aerosolizable material transport element isvisible to the user for detecting the color of the aerosolizablematerial transport element.

23. An aerosol provision system according to any of clauses 8-22,further comprising a cartridge and a control unit,

-   -   wherein the aerosolizable material transport element and the        vaporizer is located in the cartridge,    -   wherein the control unit comprises a cartridge receiving section        that includes an interface arranged to cooperatively engage with        the cartridge so as to releasably couple the cartridge to the        control unit, wherein the control unit further comprises a power        supply for delivering power to the vaporizer.

24. An aerosolizable material transport element for receivingaerosolizable material, wherein the aerosolizable material transportelement comprises at least one doping agent which is configured to colorthe aerosolizable material transport element a first color at a firstpredetermined condition, and which is configured to color theaerosolizable material transport element a second color, which isdifferent from the first color, at a second predetermined conditionwhich is different from the first predetermined condition.

25. A method of indicating a change in condition of an aerosolizablematerial transport element which is configured to receive aerosolizablematerial from a reservoir of aerosolizable material, wherein the methodcomprises:

-   -   coloring the aerosolizable material transport element a first        color at a first predetermined condition using a doping agent;        and    -   coloring the aerosolizable material transport element a second        color at a second predetermined condition, using the doping        agent, wherein the second predetermined condition is different        from the first predetermined condition.

26. A method according to clause 25, wherein the first predeterminedcondition comprises a first predetermined temperature of theaerosolizable material transport element, and the second predeterminedcondition comprises a second predetermined temperature which is higherthan the first predetermined temperature of the aerosolizable materialtransport element.

27. A method according to clause 25 or 26, wherein the aerosolizablematerial transport and the reservoir are located in an aerosol provisionsystem further comprising a vaporizer configured to vaporise theaerosolizable material received in the aerosolizable material transportelement.

28. A method according to clause 25 or 26, wherein the aerosolizablematerial transport and the reservoir are located in a cartridge for anaerosol provision system, the cartridge further comprising a vaporizerconfigured to vaporise the aerosolizable material received in theaerosolizable material transport element.

Second Set of Clauses

1. An aerosol provision system comprising:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the aerosol provision system is configured to monitor at        least one parameter of the vaporizer, which is not the        electrical resistance of the heating element, to determine a        failure state of the aerosol provision system.

2. The aerosol provision system according to clause 1, wherein theaerosol provision system further comprises control circuitry which isconfigured to determine the failure state of the aerosol provisionsystem.

3. The aerosol provision system according to clause 2, furthercomprising at least one sensor for monitoring the at least oneparameter, wherein each sensor is configured to output a sensor signalcontaining data related to the at least one parameter to the controlcircuitry;

-   -   wherein the control circuitry is configured to process the data        from the sensor signal of each sensor to determine the failure        state of the aerosol provision system.

4. The aerosol provision system of clause 3, wherein the at least oneparameter comprises a magnetic parameter of the vaporizer; and

-   -   wherein the at least one sensor comprises a first sensor for        detecting the magnetic parameter, and for outputting a first        sensor signal containing first data related to the magnetic        parameter.

5. The aerosol provision system of clause 4, wherein the magneticparameter is the magnetic field strength generated by the vaporizer, andwherein the control circuitry is further configured to:

-   -   determine a magnetic field strength value from the first data of        the first sensor signal;    -   compare the magnetic field strength value against a        predetermined magnetic field strength value; and    -   determine the failure state of the aerosol provision system in        the event that the magnetic field strength value is less than        the predetermined magnetic field strength value.

6. The aerosol provision system of clause 5, wherein the vaporizercomprises a ferromagnetic material which comprises a Curie temperaturewhich is greater than a first predetermined temperature, and which isless than a second predetermined temperature, wherein the secondpredetermined temperature is higher than the first predeterminedtemperature;

-   -   wherein the predetermined magnetic field strength value        corresponds to the magnetic field strength of the vaporizer at        the Curie temperature.

7. The aerosol provision system of clause 6, wherein the ferromagneticmaterial comprises an alloy comprising nickel and chromium.

8. The aerosol provision system of any of clauses 4-7, wherein the firstsensor comprises a Hall effect sensor.

9. The aerosol provision system of any of clauses 3-8, wherein the atleast one parameter comprises an emissivity parameter of the vaporizer;and

-   -   wherein the at least one sensor comprises a second sensor for        detecting the emissivity parameter, and for outputting a second        sensor signal containing second data related to the emissivity        parameter.

10. The aerosol provision system of clause 9, wherein the second sensorcomprises an infrared sensor.

11. The aerosol provision system of clause 9 or 10, wherein the controlcircuitry is configured to:

-   -   determine an emissivity value from the second data of the second        sensor signal; and    -   compare the emissivity value against a predetermined emissivity        value to determine the failure state of the aerosol provision        system.

12. The aerosol provision system of any of clauses 3-11, wherein the atleast one parameter comprises a frequency of vibration of the vaporizer,wherein the aerosol provision system further comprises a third sensorfor detecting the frequency of vibration of the vaporizer, wherein thethird sensor is configured to output a third sensor signal, to thecontrol circuitry, containing data related to the frequency of vibrationof the vaporizer;

-   -   wherein the control circuitry is further configured to process        the data from the third sensor signal to determine the vibration        frequency of the vaporizer; and    -   compare the vibration frequency against at least one        predetermined vibration frequency value to determine the failure        state of the aerosol provision system.

13. The aerosol provision system of any of clauses 2-12, wherein the atleast one parameter comprises a resonant frequency of the vaporizer,wherein the control circuitry is further configured to:

-   -   determine the resonant frequency of the vaporizer; and    -   compare the resonant frequency against at least one        predetermined frequency value to determine the failure state of        the aerosol provision system.

14. The aerosol provision system of any of preceding clause, furthercomprising a power supply configured to provide alternating current, AC,power to the vaporizer.

15. The aerosol provision system of clause 14, when further dependent onclause 13, wherein the control circuitry is configured to vary thefrequency of the AC power provided to the vaporizer to determine theresonant frequency of the vaporizer.

16. An aerosol provision system according to any preceding clause,wherein the failure state of the aerosol provision system comprises thevaporizer exceeding a predetermined temperature.

17. An aerosol provision system according to any preceding clause,wherein the failure state of the aerosol provision system comprises thevaporizer experiencing a dry-out state.

18. An aerosol provision system according to any of clauses 2-17,wherein response to detecting the failure state, the control circuitryis further configured to:

-   -   disable the operation of the aerosol provision system.

19. An aerosol provision system according to any of clauses 2-18,wherein response to detecting the failure state, the control circuitryis further configured to:

-   -   disable the operation of the vaporizer.

20. An aerosol provision system according to any of clauses 2-19,wherein response to detecting the failure state, the control circuitryis further configured to:

-   -   generate an output signal for providing a notification to a        user.

21. An aerosol provision system according to clause 20, wherein theoutput signal is at least one of: an optical signal, an acoustic signal,and a haptic signal.

22. An aerosol provision system according to any preceding clause,further comprising a cartridge and a control unit,

-   -   wherein the reservoir and the vaporizer are located in the        cartridge,    -   wherein the control unit comprises a cartridge receiving section        that includes an interface arranged to cooperatively engage with        the cartridge so as to releasably couple the cartridge to the        control unit.

23. The aerosol provision system of clause 22 when further dependent onclause 3, wherein the cartridge comprises the at least one sensor.

24. The aerosol provision system of clause 22 or 23 when furtherdependent on clause 14, wherein the control unit comprises the powersupply.

25. An aerosol provision system according to any preceding clause,further comprising a wick for receiving aerosolizable material from thereservoir, wherein the vaporizer is configured to vaporise theaerosolizable material received in the wick.

26. An aerosol provision system according to any preceding clause,wherein the heating element comprises a heating coil.

27. A cartridge for an aerosol provision system comprising the cartridgeand a control unit, wherein the cartridge comprises:

-   -   a reservoir for aerosolizable material; and    -   a vaporizer, comprising a heating element, for vaporising        aerosolizable material from the reservoir,    -   wherein the cartridge is configured to monitor at least one        parameter of the vaporizer, which is not the electrical        resistance of the heating element, to determine a failure state        of the cartridge.

1. An aerosol provision system comprising a reservoir for aerosolizablematerial; a wick configured to receive the aerosolizable material fromthe reservoir, a vaporizer configured to vaporize the aerosolizablematerial received in the wick, wherein the aerosol provision system isconfigured to measure at least one parameter of the wick to determine astatus of the wick.
 2. The aerosol provision system of claim 1, whereinthe status is the wick containing less than a predetermined amount ofaerosolizable material.
 3. The aerosol provision system of claim 1,wherein the status is the wick exceeding a predetermined temperature. 4.The aerosol provision system of claim 1, wherein the aerosol provisionsystem comprises control circuitry and at least one sensor for detectingthe at least one parameter; wherein each sensor is configured to outputa sensor signal containing data related to the at least one parameter;and wherein the control circuitry is configured to process the data fromthe sensor signal of each sensor to determine the status of the wick. 5.The aerosol provision system of claim 4, wherein the at least oneparameter comprises the moisture content of the wick; wherein the atleast one sensor comprises at least one load cell on which the wick issupported, wherein each load cell is configured to output a sensorsignal containing mass data related to the mass of the wick; and whereinthe control circuitry is further configured to: process the mass datafrom the sensor signal of each load cell to determine a mass value forthe wick; compare the mass value for the wick against a predeterminedmass value; and output a control signal in the event the mass value isless than the predetermined mass value.
 6. The aerosol provision systemof claim 5, wherein the at least one load cell comprises a first loadcell which supports a first end of the wick, and a second load cellwhich supports a second end of the wick.
 7. The aerosol provision systemof claim 4, wherein the at least one parameter comprises at least onephysical dimension of the wick, wherein the at least one sensorcomprises a dimension sensor for detecting the at least one physicaldimension of the wick, wherein the dimension sensor is configured tooutput a sensor signal containing dimension data related to the at leastone physical dimension of the wick; and wherein the control circuitry isfurther configured to: process the dimension data from the sensor signalof the dimension sensor to determine a dimension value for the wick;compare the dimension value for the wick against a predetermineddimension value; and output a control signal in the event the dimensionvalue is less than predetermined dimension value.
 8. The aerosolprovision system of claim 7, wherein the at least one physical dimensioncomprises a length of the wick, wherein the length extends from a firstend to a second end of the wick, and wherein the dimension data isrelated to the length of the wick.
 9. The aerosol provision system ofclaim 7, wherein the at least one physical dimension comprises a widthof the wick, and wherein the dimension data is related to the width ofthe wick.
 10. The aerosol provision system of claim 9, wherein the widthcorresponds to a width of the wick which is located between a first endand a second end of the wick, wherein the wick is configured to receivethe aerosolizable material at the first end and the second end of thewick.
 11. The aerosol provision system of claim 10, wherein the width islocated at the midpoint along a length of the wick, wherein the lengthextends from the first end and the second end.
 12. The aerosol provisionsystem of claim 4, wherein the at least one sensor comprises an opticalsensor, wherein the at least one parameter comprises an opticalparameter, and wherein the optical sensor is configured to output asensor signal containing data related to the optical parameter.
 13. Theaerosol provision system of claim 12, wherein the control circuitry isfurther configured to: process the data from the sensor signal of eachoptical sensor to determine an optical value for the wick; compare theoptical value for the wick against a predetermined optical value; andoutput a control signal in the event the optical value is greater than,and/or less than, a predetermined optical value.
 14. The aerosolprovision system of claim 12, wherein the optical parameter is thecolor, or reflectivity, of an external surface of the wick. 15.(canceled)
 16. The aerosol provision system of claim 14, wherein thewick is configured to receive the aerosolizable material from thereservoir at a first end and a second end of the wick, wherein theexternal surface of the wick is located between the first end and thesecond end.
 17. The aerosol provision system of claim 16, wherein theexternal surface is located at the midpoint along a length of the wick,wherein the length extends from the first end and the second end. 18.The aerosol provision system of claim 5, wherein the control signalcomprises a command to disable the operation of the aerosol provisionsystem.
 19. The aerosol provision system of claim 5 wherein the controlsignal comprises a command to; i) disable the operation of thevaporizer, and/or ii) provide a notification to a user. 20-21.(canceled)
 22. The aerosol provision system rep of claim 1, wherein theaerosol provision system comprises at least one doping agent which isconfigured to color the wick a first color at a first predeterminedcondition, and which is configured to color the wick a second color,which is different from the first color, at a second predeterminedcondition which is different from the first predetermined condition. 23.The aerosol provision system of claim 22, wherein the wick comprises thedoping agent.
 24. The aerosol provision system of claim 22, furthercomprising the aerosolizable material in the reservoir, wherein theaerosolizable material comprises the doping agent.
 25. The aerosolprovision system of claim 22, wherein the doping agent comprises ahydrochromic material.
 26. The aerosol provision system of claim 22,wherein the first predetermined condition comprises a first moisturecontent of the wick, and the second predetermined condition comprises asecond moisture content of the wick which is less than the firstmoisture content.
 27. The aerosol provision system of claim 22, whereinthe doping agent comprises a thermochromic material.
 28. The aerosolprovision system of claim 22, wherein the first predetermined conditioncomprises a first predetermined temperature of the wick, and the secondpredetermined condition comprises a second predetermined temperaturewhich is higher than the first predetermined temperature of the wick.29. (canceled)
 30. The aerosol provision system of claim 1, furthercomprising a cartridge and a control unit, wherein the reservoir islocated in the cartridge, wherein the control unit comprises a cartridgereceiving section that includes an interface arranged to cooperativelyengage with the cartridge so as to releasably couple the cartridge tothe control unit, wherein the control unit further comprises a powersupply for delivering power to the vaporizer. 31-34. (canceled)
 35. Acartridge for an aerosol provision system comprising the cartridge and acontrol unit, wherein the cartridge comprises: a reservoir foraerosolizable material; a wick configured to receive the aerosolizablematerial from the reservoir; and a vaporizer configured to vaporize theaerosolizable material received in the wick, wherein the cartridge isconfigured to measure at least one parameter of the wick to determine astatus of the wick. 36-90. (canceled)